Re: Time question on GPS TIME and leap second.
;> for a leapday calendar such as he proposes. But for a leapweek calendar, >>> which is what I (and many others) propose, a new leapyear system is >>> required. No problem. I'll get to that after I discuss my disagreements >>> with Gorman's proposal. >>> >>> Summary: A fixed calendar should be achieved via a leapweek, instead of >>> by >>> blank-days. If Achellis had agreed to that, we might be using her >>> calendar >>> right now. >>> >>> *2. Thirteen Months:* >>> >>> Really, the only reason for a reform calendar to have months, is for >>> continuity & familiarity with our current Roman-Gregorian Calendar. >>> >>> For example, Elizabeth Achellis's *World Calendar *had, in each quarter, >>> >>> months with the following lengths: 31,30,30. Having 12 months, with 30 >>> or >>> 30 or 31 days, means that the calendar is familiar, looks familiar, and >>> it >>> means that the dates in the new calendar have really the same seasonal >>> meaning as the dates in the old calendar. >>> >>> Achellis' 31,30,30 quarters achieves that. But there are other proposals >>> of a calendar with >>> 30,30,31 quarters. The advantage?: >>> >>> 1. The 30,30,31 calendar's months' start-days never differ by more than a >>> day, from those of our current Roman months, when both month-systems >>> start >>> on the same day. Achellis' 31,30,30 quarter system can differ by at least >>> twice as much. >>> >>> 2. The 30,30,31 quarters divide the weekdays most equally between the >>> months of the quarter. >>> >>> So, if you're going to have months at all (and that's for continuity & >>> familiarity), then you want 12 months, of 30 & 31 days. Preferably the >>> 30,30,31 quarters. >>> >>> With 13 months of 28 days, the dates wouldn't have anything like the >>> seasonal meaning that they do now. Continuity, familiarity, and the >>> justification for having months at all, would be lost. >>> >>> The 30,30,31 quarter system is an improvement over our current Roman >>> months, because the months are much more uniform. That allows much >>> meaningful & accurate monthly statistics. >>> >>> But suppose you want something more radical (as is Gorman's 28X13 >>> system): >>> >>> In that case, just don't have months, because their continuity & >>> familiarity purpose would be lost anyway. Use the WeekDate system. >>> >>> No months. >>> >>> Weeks are numbered. >>> >>> Here's today's date in the (currently internationally widely-used) ISO >>> WeekDate calendar: >>> >>> 4 Saturday >>> >>> That means Saturday of the 4th week. >>> >>> Actually, because not all countries and languages call the da >>> >>> ys of the week by the same names, here is how the ISO (International >>> Standards Organization) words today's date. >>> >>> 2017W046 >>> >>> The "W" indicates that the WeekDate system is being used. >>> >>> The "04" denotes the 4th week. >>> >>> The "6" denotes the 6th day of that week. >>> >>> (The ISO WeekDate Calendar uses a week (and therefore a year) that begins >>> on a Monday, probably so that the weekend won't be split in half.) >>> >>> The ISO WeekDate Calendar is, as I said, widely used internationally, by >>> Companies & Governments, for their planning of business & governmental >>> dates & events. ...making it easy to plan them in advance once, and then >>> leave them, because it's a fixed calendar. Of course the resulting dates >>> then have to be eventually translated into Roman-Gregorian dates. >>> >>> >>> ...but they wouldn't have to, if we adopted the ISO WeekDate calendar as >>> our civil calendar, worldwide. >>> >>> ISO WeekDate has the great advantage of use-precedent. ...lots of it. >>> >>> I personally like the ISO WeekDate as the best calendar-reform proposal. >>> >>> But, recognizing that many people wouldn't want to give up the months, >>> and >>> would want to keep them for familiarity & continuity, the 30,30,31 >>> month-system could be a good alternative proposal, if ISO WeekDate isn't >>> accepted. >>> >>> But it has been argued that ISO WeekDate is so convenie
AW: Time question on GPS TIME and leap second.
ar *had, in each quarter, >>> >>> months with the following lengths: 31,30,30. Having 12 months, with 30 >>> or >>> 30 or 31 days, means that the calendar is familiar, looks familiar, and >>> it >>> means that the dates in the new calendar have really the same seasonal >>> meaning as the dates in the old calendar. >>> >>> Achellis' 31,30,30 quarters achieves that. But there are other proposals >>> of a calendar with >>> 30,30,31 quarters. The advantage?: >>> >>> 1. The 30,30,31 calendar's months' start-days never differ by more than a >>> day, from those of our current Roman months, when both month-systems >>> start >>> on the same day. Achellis' 31,30,30 quarter system can differ by at least >>> twice as much. >>> >>> 2. The 30,30,31 quarters divide the weekdays most equally between the >>> months of the quarter. >>> >>> So, if you're going to have months at all (and that's for continuity & >>> familiarity), then you want 12 months, of 30 & 31 days. Preferably the >>> 30,30,31 quarters. >>> >>> With 13 months of 28 days, the dates wouldn't have anything like the >>> seasonal meaning that they do now. Continuity, familiarity, and the >>> justification for having months at all, would be lost. >>> >>> The 30,30,31 quarter system is an improvement over our current Roman >>> months, because the months are much more uniform. That allows much >>> meaningful & accurate monthly statistics. >>> >>> But suppose you want something more radical (as is Gorman's 28X13 >>> system): >>> >>> In that case, just don't have months, because their continuity & >>> familiarity purpose would be lost anyway. Use the WeekDate system. >>> >>> No months. >>> >>> Weeks are numbered. >>> >>> Here's today's date in the (currently internationally widely-used) ISO >>> WeekDate calendar: >>> >>> 4 Saturday >>> >>> That means Saturday of the 4th week. >>> >>> Actually, because not all countries and languages call the da >>> >>> ys of the week by the same names, here is how the ISO (International >>> Standards Organization) words today's date. >>> >>> 2017W046 >>> >>> The "W" indicates that the WeekDate system is being used. >>> >>> The "04" denotes the 4th week. >>> >>> The "6" denotes the 6th day of that week. >>> >>> (The ISO WeekDate Calendar uses a week (and therefore a year) that begins >>> on a Monday, probably so that the weekend won't be split in half.) >>> >>> The ISO WeekDate Calendar is, as I said, widely used internationally, by >>> Companies & Governments, for their planning of business & governmental >>> dates & events. ...making it easy to plan them in advance once, and then >>> leave them, because it's a fixed calendar. Of course the resulting dates >>> then have to be eventually translated into Roman-Gregorian dates. >>> >>> >>> ...but they wouldn't have to, if we adopted the ISO WeekDate calendar as >>> our civil calendar, worldwide. >>> >>> ISO WeekDate has the great advantage of use-precedent. ...lots of it. >>> >>> I personally like the ISO WeekDate as the best calendar-reform proposal. >>> >>> But, recognizing that many people wouldn't want to give up the months, >>> and >>> would want to keep them for familiarity & continuity, the 30,30,31 >>> month-system could be a good alternative proposal, if ISO WeekDate isn't >>> accepted. >>> >>> But it has been argued that ISO WeekDate is so convenient, and already so >>> widely-used, that it could easily edge-out the Roman-Gregorian Calendar, >>> from the bottom up, by increasingly wide use, if companies & government >>> start using it so much that the public start finding it convenient to use >>> it too. >>> >>> So those are my two disagreements with Gorman's proposal, and my >>> alternative suggestions. >>> >>> But I should comment on the leapyear rule. Actually, the ISO WeekDate >>> Calendar deals with that in a really easy, natural, simple & obvious way. >>> >>> Each ISO WeekDate year starts on whatever Monday is closest to the >>> Gregorian January 1st of that year. So, for example, this year, 2017, the >>> Gregorian year started on a Sunday. So the nearest Monday to Gregorian >>> January 1st was January 2nd. That Monday, Gregorian January 2nd, is the >>> day >>> on which ISO WeekDate 2017 started. >>> >>> As I said, today, in the ISO WeekDate Calendar, is: >>> >>> 4 Saturday >>> >>> (or 2017W046) >>> >>> That way of defining the start of the ISO WeekDate year (the Monday >>> closes >>> to Gregorian January 1st) is called the Nearest-Monday year-start system. >>> >>> Note that the Nearest-Monday year-start system doen't have to mention >>> leapyears or leapweeks at all. It's *effectively* a leapweek calendar, >>> because some of the years have 53 weeks instead of 52. But the simple >>> Nearest-Monday year-start rule doesn't need to mention leapyears or >>> leapweeks. >>> >>> Not only is it used with the ISO WeekDate Calendar, but of course it >>> could >>> also be used with a 30,30,31 quarters calendar too. >>> >>> Calendar reform advocates propose all manner of different leapyear >>> systems. But there's nothing wrong with the Nearest-Monday year-start >>> system, and conversations have suggested to me that Nearest-Monday would >>> be >>> the favorite way to make a fixed calendar. >>> >>> In fact, with Nearest-Monday, the maximum displacement of dates with >>> respect to seasons, is barely more than the ideal minimum that could be >>> achieved by the fanciest leapyear system. >>> >>> I also propose a fancier, deluxely-adjustable system, but I won't try >>> your >>> patience with that here, because Nearest-Monday is entirely good enough, >>> and is the system with obviously by far the best acceptance-potential. >>> >>> Michael Ossipoff. >>> >>> >>> >>> >>> >>> >>> On Sat, Jan 28, 2017 at 3:38 PM, Dan-George Uza <cerculdest...@gmail.com <mailto:cerculdest...@gmail.com> >>> > >>> wrote: >>> >>> A bit off topic, but I enjoyed this quite a lot! >>>> >>>> https://youtu.be/EcMTHr3TqA0 >>>> >>>> Dan >>>> >>>> --- >>>> https://lists.uni-koeln.de/mailman/listinfo/sundial >>>> >>>> >>>> >>>> -- next part -- >> An HTML attachment was scrubbed... >> URL: <https://lists.uni-koeln.de/mailman/private/sundial/attachme >> nts/20170129/9cea9958/attachment.html> >> >> -- >> >> Subject: Digest Footer >> >> ___ >> sundial mailing list >> sundial@uni-koeln.de <mailto:sundial@uni-koeln.de> >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> -- >> >> End of sundial Digest, Vol 133, Issue 27 >> >> >> > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Time question on GPS TIME and leap second.
rt-days never differ by more than a >>> day, from those of our current Roman months, when both month-systems >>> start >>> on the same day. Achellis' 31,30,30 quarter system can differ by at least >>> twice as much. >>> >>> 2. The 30,30,31 quarters divide the weekdays most equally between the >>> months of the quarter. >>> >>> So, if you're going to have months at all (and that's for continuity & >>> familiarity), then you want 12 months, of 30 & 31 days. Preferably the >>> 30,30,31 quarters. >>> >>> With 13 months of 28 days, the dates wouldn't have anything like the >>> seasonal meaning that they do now. Continuity, familiarity, and the >>> justification for having months at all, would be lost. >>> >>> The 30,30,31 quarter system is an improvement over our current Roman >>> months, because the months are much more uniform. That allows much >>> meaningful & accurate monthly statistics. >>> >>> But suppose you want something more radical (as is Gorman's 28X13 >>> system): >>> >>> In that case, just don't have months, because their continuity & >>> familiarity purpose would be lost anyway. Use the WeekDate system. >>> >>> No months. >>> >>> Weeks are numbered. >>> >>> Here's today's date in the (currently internationally widely-used) ISO >>> WeekDate calendar: >>> >>> 4 Saturday >>> >>> That means Saturday of the 4th week. >>> >>> Actually, because not all countries and languages call the da >>> >>> ys of the week by the same names, here is how the ISO (International >>> Standards Organization) words today's date. >>> >>> 2017W046 >>> >>> The "W" indicates that the WeekDate system is being used. >>> >>> The "04" denotes the 4th week. >>> >>> The "6" denotes the 6th day of that week. >>> >>> (The ISO WeekDate Calendar uses a week (and therefore a year) that begins >>> on a Monday, probably so that the weekend won't be split in half.) >>> >>> The ISO WeekDate Calendar is, as I said, widely used internationally, by >>> Companies & Governments, for their planning of business & governmental >>> dates & events. ...making it easy to plan them in advance once, and then >>> leave them, because it's a fixed calendar. Of course the resulting dates >>> then have to be eventually translated into Roman-Gregorian dates. >>> >>> >>> ...but they wouldn't have to, if we adopted the ISO WeekDate calendar as >>> our civil calendar, worldwide. >>> >>> ISO WeekDate has the great advantage of use-precedent. ...lots of it. >>> >>> I personally like the ISO WeekDate as the best calendar-reform proposal. >>> >>> But, recognizing that many people wouldn't want to give up the months, >>> and >>> would want to keep them for familiarity & continuity, the 30,30,31 >>> month-system could be a good alternative proposal, if ISO WeekDate isn't >>> accepted. >>> >>> But it has been argued that ISO WeekDate is so convenient, and already so >>> widely-used, that it could easily edge-out the Roman-Gregorian Calendar, >>> from the bottom up, by increasingly wide use, if companies & government >>> start using it so much that the public start finding it convenient to use >>> it too. >>> >>> So those are my two disagreements with Gorman's proposal, and my >>> alternative suggestions. >>> >>> But I should comment on the leapyear rule. Actually, the ISO WeekDate >>> Calendar deals with that in a really easy, natural, simple & obvious way. >>> >>> Each ISO WeekDate year starts on whatever Monday is closest to the >>> Gregorian January 1st of that year. So, for example, this year, 2017, the >>> Gregorian year started on a Sunday. So the nearest Monday to Gregorian >>> January 1st was January 2nd. That Monday, Gregorian January 2nd, is the >>> day >>> on which ISO WeekDate 2017 started. >>> >>> As I said, today, in the ISO WeekDate Calendar, is: >>> >>> 4 Saturday >>> >>> (or 2017W046) >>> >>> That way of defining the start of the ISO WeekDate year (the Monday >>> closes >>> to Gregorian January 1st) is called the Nearest-Monday year-start system. >>> >>> Note that the Nearest-Monday year-start system doen't have to mention >>> leapyears or leapweeks at all. It's *effectively* a leapweek calendar, >>> because some of the years have 53 weeks instead of 52. But the simple >>> Nearest-Monday year-start rule doesn't need to mention leapyears or >>> leapweeks. >>> >>> Not only is it used with the ISO WeekDate Calendar, but of course it >>> could >>> also be used with a 30,30,31 quarters calendar too. >>> >>> Calendar reform advocates propose all manner of different leapyear >>> systems. But there's nothing wrong with the Nearest-Monday year-start >>> system, and conversations have suggested to me that Nearest-Monday would >>> be >>> the favorite way to make a fixed calendar. >>> >>> In fact, with Nearest-Monday, the maximum displacement of dates with >>> respect to seasons, is barely more than the ideal minimum that could be >>> achieved by the fanciest leapyear system. >>> >>> I also propose a fancier, deluxely-adjustable system, but I won't try >>> your >>> patience with that here, because Nearest-Monday is entirely good enough, >>> and is the system with obviously by far the best acceptance-potential. >>> >>> Michael Ossipoff. >>> >>> >>> >>> >>> >>> >>> On Sat, Jan 28, 2017 at 3:38 PM, Dan-George Uza >>> <cerculdest...@gmail.com<mailto:cerculdest...@gmail.com> >>> > >>> wrote: >>> >>> A bit off topic, but I enjoyed this quite a lot! >>>> >>>> https://youtu.be/EcMTHr3TqA0 >>>> >>>> Dan >>>> >>>> --- >>>> https://lists.uni-koeln.de/mailman/listinfo/sundial >>>> >>>> >>>> >>>> -- next part -- >> An HTML attachment was scrubbed... >> URL: <https://lists.uni-koeln.de/mailman/private/sundial/attachme >> nts/20170129/9cea9958/attachment.html> >> >> -- >> >> Subject: Digest Footer >> >> ___ >> sundial mailing list >> sundial@uni-koeln.de<mailto:sundial@uni-koeln.de> >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> -- >> >> End of sundial Digest, Vol 133, Issue 27 >> >> >> > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Why we should reform the Calendar
*The Minimum-Displacement Leapyear Rule:* This is a leap-week leapyear-rule. The common (non-leap) year is 364 days long. A leapyear is 364 + 7 = 371 days long. The leapweek is added at the end of the year, becoming part of that year Epoch: Gregorian January 2, 2017 is this calendar's start, being this calendar's January 1, 2017.. *Variable: * D D stands for "displacement". Though this definition isn't needed for the specification of this leapyear-rule, displacement is a change or difference in the relation between date and ecliptic longitude. Actually the progress of a mean-year, or an approximation to one, usually stands in for ecliptic longitude in a leapyear-rule. D, here, is the difference between the current year's displacement from the year's desired relation between date & ecliptic longitude (where ecliptic longitude is represented by the progress of the mean-year). *Constants:* 1. Dzero is the starting value of D, the value of D at the calendar's epoch. (The epoch is the time at which the calendar is defined to start). 2. Y is the length of the leapyear-rule's mean-year (I sometimes call it the "reference-year" too). For the value of Dzero, I offer -.6288 or 0. Of those two, I recommend -.6288 (...for reasons I'll get to later in this post.) A Dzero of -.6288 means that the year is, at its epoch, displaced by -.6288 days from its desired relation of date & season. For the value of Y, I recommend 365.24217, the approximate number of mean solar days in a mean tropical year (MTY). Dzero & Y are the two adjustment-parameters that I spoke of in a previous post. *Year-End Change in D:* At the end of a calendar year (whether common or leap), the value of D changes by an amount equal to Y minus the length of that year in days. If that change would otherwise result in a D value greater than +3.5, then 7 days are added to the end of that year, before implementing the paragraph before this one. ...making that year a leapyear. [end of Minimum-Displacement leapyear-rule] In this way, the value of D is kept within the limits of -3.5 days to + 3.5 days. D is a good measure of the calendar's displacement from its desired date/season relation defined by Dzero. The -.6288 value of Dzero is consistent with a desired relation of calendar-date and ecliptic-longitude (...where ecliptic-longitude is represented by the progress of the 365.24217 day mean-year) that is the midpoint of the extremes of the values that that relation had between January 1, 1950 and January 1, 2017. ...in order that the calendar's center of displacement-oscillation be the average of its variation-extremes since January 1, 1950. ...so that the calendar's date-season relation will stay close to where it has been during the experience of currently-living humans. Though I like the ISO WeekDate calendar, and it's said that it has a good chance of eventually displacing Roman-Gregorian, via gradually-increasing usage, my proposal is a calendar using the 30,30,31 quarters, and the Minimum-Displacement leapyear-rule, with Dzero = -.6288, and with Y = 365.24217. I should add that calculation, with the Minimum-Displacement rule, of durations, day-of-the-week, & displacements are no more difficult than the same calculations with the Gregorian leapyear-rule. And determination of whether a particular far-distant year is a leapyear is no more difficult than those calculations. ...and of course the determination of whether the *next* year is a leapyear is just a matter of directly applying the leapyear-rule, as defined above. . ..and of course, any time when the current year is a leapyear, that fact will be amply announced long before the end of that year. Michael Ossipoff approx. 26N, 80W --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Time question on GPS TIME and leap second.
gt;> The 30,30,31 quarter system is an improvement over our current Roman >>> months, because the months are much more uniform. That allows much >>> meaningful & accurate monthly statistics. >>> >>> But suppose you want something more radical (as is Gorman's 28X13 >>> system): >>> >>> In that case, just don't have months, because their continuity & >>> familiarity purpose would be lost anyway. Use the WeekDate system. >>> >>> No months. >>> >>> Weeks are numbered. >>> >>> Here's today's date in the (currently internationally widely-used) ISO >>> WeekDate calendar: >>> >>> 4 Saturday >>> >>> That means Saturday of the 4th week. >>> >>> Actually, because not all countries and languages call the da >>> >>> ys of the week by the same names, here is how the ISO (International >>> Standards Organization) words today's date. >>> >>> 2017W046 >>> >>> The "W" indicates that the WeekDate system is being used. >>> >>> The "04" denotes the 4th week. >>> >>> The "6" denotes the 6th day of that week. >>> >>> (The ISO WeekDate Calendar uses a week (and therefore a year) that begins >>> on a Monday, probably so that the weekend won't be split in half.) >>> >>> The ISO WeekDate Calendar is, as I said, widely used internationally, by >>> Companies & Governments, for their planning of business & governmental >>> dates & events. ...making it easy to plan them in advance once, and then >>> leave them, because it's a fixed calendar. Of course the resulting dates >>> then have to be eventually translated into Roman-Gregorian dates. >>> >>> >>> ...but they wouldn't have to, if we adopted the ISO WeekDate calendar as >>> our civil calendar, worldwide. >>> >>> ISO WeekDate has the great advantage of use-precedent. ...lots of it. >>> >>> I personally like the ISO WeekDate as the best calendar-reform proposal. >>> >>> But, recognizing that many people wouldn't want to give up the months, >>> and >>> would want to keep them for familiarity & continuity, the 30,30,31 >>> month-system could be a good alternative proposal, if ISO WeekDate isn't >>> accepted. >>> >>> But it has been argued that ISO WeekDate is so convenient, and already so >>> widely-used, that it could easily edge-out the Roman-Gregorian Calendar, >>> from the bottom up, by increasingly wide use, if companies & government >>> start using it so much that the public start finding it convenient to use >>> it too. >>> >>> So those are my two disagreements with Gorman's proposal, and my >>> alternative suggestions. >>> >>> But I should comment on the leapyear rule. Actually, the ISO WeekDate >>> Calendar deals with that in a really easy, natural, simple & obvious way. >>> >>> Each ISO WeekDate year starts on whatever Monday is closest to the >>> Gregorian January 1st of that year. So, for example, this year, 2017, the >>> Gregorian year started on a Sunday. So the nearest Monday to Gregorian >>> January 1st was January 2nd. That Monday, Gregorian January 2nd, is the >>> day >>> on which ISO WeekDate 2017 started. >>> >>> As I said, today, in the ISO WeekDate Calendar, is: >>> >>> 4 Saturday >>> >>> (or 2017W046) >>> >>> That way of defining the start of the ISO WeekDate year (the Monday >>> closes >>> to Gregorian January 1st) is called the Nearest-Monday year-start system. >>> >>> Note that the Nearest-Monday year-start system doen't have to mention >>> leapyears or leapweeks at all. It's *effectively* a leapweek calendar, >>> because some of the years have 53 weeks instead of 52. But the simple >>> Nearest-Monday year-start rule doesn't need to mention leapyears or >>> leapweeks. >>> >>> Not only is it used with the ISO WeekDate Calendar, but of course it >>> could >>> also be used with a 30,30,31 quarters calendar too. >>> >>> Calendar reform advocates propose all manner of different leapyear >>> systems. But there's nothing wrong with the Nearest-Monday year-start >>> system, and conversations have suggested to me that Nearest-Monday would >>> be >>> the favorite way to make a fixed calendar. >>> >>> In fact, with Nearest-Monday, the maximum displacement of dates with >>> respect to seasons, is barely more than the ideal minimum that could be >>> achieved by the fanciest leapyear system. >>> >>> I also propose a fancier, deluxely-adjustable system, but I won't try >>> your >>> patience with that here, because Nearest-Monday is entirely good enough, >>> and is the system with obviously by far the best acceptance-potential. >>> >>> Michael Ossipoff. >>> >>> >>> >>> >>> >>> >>> On Sat, Jan 28, 2017 at 3:38 PM, Dan-George Uza <cerculdest...@gmail.com >>> > >>> wrote: >>> >>> A bit off topic, but I enjoyed this quite a lot! >>>> >>>> https://youtu.be/EcMTHr3TqA0 >>>> >>>> Dan >>>> >>>> --- >>>> https://lists.uni-koeln.de/mailman/listinfo/sundial >>>> >>>> >>>> >>>> -- next part -- >> An HTML attachment was scrubbed... >> URL: <https://lists.uni-koeln.de/mailman/private/sundial/attachme >> nts/20170129/9cea9958/attachment.html> >> >> -- >> >> Subject: Digest Footer >> >> ___ >> sundial mailing list >> sundial@uni-koeln.de >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> -- >> >> End of sundial Digest, Vol 133, Issue 27 >> >> >> > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >--- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Why we should reform the Calendar
date in the (currently internationally widely-used) ISO >>> WeekDate calendar: >>> >>> 4 Saturday >>> >>> That means Saturday of the 4th week. >>> >>> Actually, because not all countries and languages call the da >>> >>> ys of the week by the same names, here is how the ISO (International >>> Standards Organization) words today's date. >>> >>> 2017W046 >>> >>> The "W" indicates that the WeekDate system is being used. >>> >>> The "04" denotes the 4th week. >>> >>> The "6" denotes the 6th day of that week. >>> >>> (The ISO WeekDate Calendar uses a week (and therefore a year) that begins >>> on a Monday, probably so that the weekend won't be split in half.) >>> >>> The ISO WeekDate Calendar is, as I said, widely used internationally, by >>> Companies & Governments, for their planning of business & governmental >>> dates & events. ...making it easy to plan them in advance once, and then >>> leave them, because it's a fixed calendar. Of course the resulting dates >>> then have to be eventually translated into Roman-Gregorian dates. >>> >>> >>> ...but they wouldn't have to, if we adopted the ISO WeekDate calendar as >>> our civil calendar, worldwide. >>> >>> ISO WeekDate has the great advantage of use-precedent. ...lots of it. >>> >>> I personally like the ISO WeekDate as the best calendar-reform proposal. >>> >>> But, recognizing that many people wouldn't want to give up the months, >>> and >>> would want to keep them for familiarity & continuity, the 30,30,31 >>> month-system could be a good alternative proposal, if ISO WeekDate isn't >>> accepted. >>> >>> But it has been argued that ISO WeekDate is so convenient, and already so >>> widely-used, that it could easily edge-out the Roman-Gregorian Calendar, >>> from the bottom up, by increasingly wide use, if companies & government >>> start using it so much that the public start finding it convenient to use >>> it too. >>> >>> So those are my two disagreements with Gorman's proposal, and my >>> alternative suggestions. >>> >>> But I should comment on the leapyear rule. Actually, the ISO WeekDate >>> Calendar deals with that in a really easy, natural, simple & obvious way. >>> >>> Each ISO WeekDate year starts on whatever Monday is closest to the >>> Gregorian January 1st of that year. So, for example, this year, 2017, the >>> Gregorian year started on a Sunday. So the nearest Monday to Gregorian >>> January 1st was January 2nd. That Monday, Gregorian January 2nd, is the >>> day >>> on which ISO WeekDate 2017 started. >>> >>> As I said, today, in the ISO WeekDate Calendar, is: >>> >>> 4 Saturday >>> >>> (or 2017W046) >>> >>> That way of defining the start of the ISO WeekDate year (the Monday >>> closes >>> to Gregorian January 1st) is called the Nearest-Monday year-start system. >>> >>> Note that the Nearest-Monday year-start system doen't have to mention >>> leapyears or leapweeks at all. It's *effectively* a leapweek calendar, >>> because some of the years have 53 weeks instead of 52. But the simple >>> Nearest-Monday year-start rule doesn't need to mention leapyears or >>> leapweeks. >>> >>> Not only is it used with the ISO WeekDate Calendar, but of course it >>> could >>> also be used with a 30,30,31 quarters calendar too. >>> >>> Calendar reform advocates propose all manner of different leapyear >>> systems. But there's nothing wrong with the Nearest-Monday year-start >>> system, and conversations have suggested to me that Nearest-Monday would >>> be >>> the favorite way to make a fixed calendar. >>> >>> In fact, with Nearest-Monday, the maximum displacement of dates with >>> respect to seasons, is barely more than the ideal minimum that could be >>> achieved by the fanciest leapyear system. >>> >>> I also propose a fancier, deluxely-adjustable system, but I won't try >>> your >>> patience with that here, because Nearest-Monday is entirely good enough, >>> and is the system with obviously by far the best acceptance-potential. >>> >>> Michael Ossipoff. >>> >>> >>> >>> >>> >>> >>> On Sat, Jan 28, 2017 at 3:38 PM, Dan-George Uza <cerculdest...@gmail.com >>> > >>> wrote: >>> >>> A bit off topic, but I enjoyed this quite a lot! >>>> >>>> https://youtu.be/EcMTHr3TqA0 >>>> >>>> Dan >>>> >>>> --- >>>> https://lists.uni-koeln.de/mailman/listinfo/sundial >>>> >>>> >>>> >>>> -- next part -- >> An HTML attachment was scrubbed... >> URL: <https://lists.uni-koeln.de/mailman/private/sundial/attachme >> nts/20170129/9cea9958/attachment.html> >> >> -- >> >> Subject: Digest Footer >> >> ___ >> sundial mailing list >> sundial@uni-koeln.de >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> >> >> -- >> >> End of sundial Digest, Vol 133, Issue 27 >> >> >> > --- > https://lists.uni-koeln.de/mailman/listinfo/sundial > > --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Why we should reform the Calendar
d languages call the da ys of the week by the same names, here is how the ISO (International Standards Organization) words today's date. 2017W046 The "W" indicates that the WeekDate system is being used. The "04" denotes the 4th week. The "6" denotes the 6th day of that week. (The ISO WeekDate Calendar uses a week (and therefore a year) that begins on a Monday, probably so that the weekend won't be split in half.) The ISO WeekDate Calendar is, as I said, widely used internationally, by Companies & Governments, for their planning of business & governmental dates & events. ...making it easy to plan them in advance once, and then leave them, because it's a fixed calendar. Of course the resulting dates then have to be eventually translated into Roman-Gregorian dates. ...but they wouldn't have to, if we adopted the ISO WeekDate calendar as our civil calendar, worldwide. ISO WeekDate has the great advantage of use-precedent. ...lots of it. I personally like the ISO WeekDate as the best calendar-reform proposal. But, recognizing that many people wouldn't want to give up the months, and would want to keep them for familiarity & continuity, the 30,30,31 month-system could be a good alternative proposal, if ISO WeekDate isn't accepted. But it has been argued that ISO WeekDate is so convenient, and already so widely-used, that it could easily edge-out the Roman-Gregorian Calendar, from the bottom up, by increasingly wide use, if companies & government start using it so much that the public start finding it convenient to use it too. So those are my two disagreements with Gorman's proposal, and my alternative suggestions. But I should comment on the leapyear rule. Actually, the ISO WeekDate Calendar deals with that in a really easy, natural, simple & obvious way. Each ISO WeekDate year starts on whatever Monday is closest to the Gregorian January 1st of that year. So, for example, this year, 2017, the Gregorian year started on a Sunday. So the nearest Monday to Gregorian January 1st was January 2nd. That Monday, Gregorian January 2nd, is the day on which ISO WeekDate 2017 started. As I said, today, in the ISO WeekDate Calendar, is: 4 Saturday (or 2017W046) That way of defining the start of the ISO WeekDate year (the Monday closes to Gregorian January 1st) is called the Nearest-Monday year-start system. Note that the Nearest-Monday year-start system doen't have to mention leapyears or leapweeks at all. It's *effectively* a leapweek calendar, because some of the years have 53 weeks instead of 52. But the simple Nearest-Monday year-start rule doesn't need to mention leapyears or leapweeks. Not only is it used with the ISO WeekDate Calendar, but of course it could also be used with a 30,30,31 quarters calendar too. Calendar reform advocates propose all manner of different leapyear systems. But there's nothing wrong with the Nearest-Monday year-start system, and conversations have suggested to me that Nearest-Monday would be the favorite way to make a fixed calendar. In fact, with Nearest-Monday, the maximum displacement of dates with respect to seasons, is barely more than the ideal minimum that could be achieved by the fanciest leapyear system. I also propose a fancier, deluxely-adjustable system, but I won't try your patience with that here, because Nearest-Monday is entirely good enough, and is the system with obviously by far the best acceptance-potential. Michael Ossipoff. On Sat, Jan 28, 2017 at 3:38 PM, Dan-George Uza <cerculdest...@gmail.com> wrote: A bit off topic, but I enjoyed this quite a lot! https://youtu.be/EcMTHr3TqA0 Dan --- https://lists.uni-koeln.de/mailman/listinfo/sundial -- next part -- An HTML attachment was scrubbed... URL: <https://lists.uni-koeln.de/mailman/private/sundial/attachments/20170129/9cea9958/attachment.html> -- Subject: Digest Footer ___ sundial mailing list sundial@uni-koeln.de https://lists.uni-koeln.de/mailman/listinfo/sundial -- End of sundial Digest, Vol 133, Issue 27 --- https://lists.uni-koeln.de/mailman/listinfo/sundial
Re: Why we should reform the Calendar
Here are two (unimportant) objections to the Nearest-Monday year-start system: 1. It's based on the Gregorian leapyear-rule, meaning that it isn't self-contained & free-standing. Mostly an aesthetic objection, and I don't consider it important. 2. It inherits certain properties of the Gregorian Calendar, which could otherwise be adjustable, choose-able. This, too, I consider only an aesthetic objection. Here are the properties that I refer to: The Gregorian leapyear-rule was designed to minimize the date's variation at the (northern) Vernal Equinox, the March equinox. We often hear it said that the mean tropical year is the time from one March equinox to the next. Not so. That's because the length of a tropical year depends on at what point of the ecliptic it's measured. A tropical year is a seasonal year, the time during which the center of the sun leaves & returns to some particular point of the ecliptic. That duration is different, depending on the point of the ecliptic at which it's measured. That's because the Earth's orbit is continuously changing, due to perturbation by other planets, mostly Jupiter. So, for example, the following tropical years have different durations: The March Equinox year, the September Equinox year, the June Solstice year, and the December Solstice year. Leapyear-rules try to achieve some desired "mean year". The Gregorian leapyear-rule's mean-year is 365.2425 days. Probably mean solar days, I assume. As I said, the Gregorian's mean-year is intended to approximate the March Equinox year. A mean solar day is the duration between meridian-transits of the mean sun. The mean sun is a fictitious sun that goes around the celestial equator at a constant rate, coinciding at the equinoxes with another fictitious sun that goes around the ecliptic at a constant rate and coincides with the real sun at aphelion & perihelion. Often the length of (various kinds of) a tropical year is given in ephemeris days (defined in terms of planetary motions), also callled atomic days.(when defined in terms of atomic clock measurements). The length of an ephemeris day was fixed in the early 19th century. But, since then, the length of the day has increased a bit, and so the ephemeris day no longer matches the mean solar day. For example, we often hear it said that a mean tropical year is 365.24219 days. But that's ephemeris days. According to a Wikipedia article (calendarists that I've spoken with haven't expressed disagreement with it), a mean tropical year is actually currently about 365.24217 mean solar days. The length of the mean tropical year is the (current value of the) arithmetic mean of the lengths of the tropical year measured at all the points of the ecliptic. So, if you calculated two Earth orbits, accounting for planetary perturbations. recording the time at many different points of the ecliptic, and then used those times to calculate the tropical year with respect to those many points of the ecliptic, and then, over one circuit around the ecliptic, numerically integrated the tropical-year-length, with respect to ecliptic longitude, and then divided by 2 pi radians ( = 360 degrees), that would give you the length of a mean tropical year. As I said, according to Wikipedia, it's currently about 364.24217 days. So, anyway, the Gregorian leapyear rule's mean-year, of 365.2425 days is intended as an approximation of the March equinox year of about (it seems to me) 365.24239 days. It's understandable that they chose to favor the Vernal Equinox year. The equinoxes are the time when the solar declination is changing fastest, and when the season is changing fastest. Problem: The Northern Hemisphere's Vernal Equinox isn't the Southern Hemisphere's Vernal Equinox. The Vernal Equinox, near the beginning of Spring, is a revered, honored & celebrated time. But why should the people of the Southern Hemisphere celebrate the *northern* Vernal Equinox? In 1582 that wasn't a problem for Europeans. But this is a different century now. In this century, choosing the northern Vernal Equinox as the basis for the calendar's mean year is more than a little north-chauvinistic and inegalitarian. So I'd prefer to use an approximation to the mean tropical year, instead of the March equinox year, as a leapyear-rule's mean year. That's what my leapyear-rule proposal does. (I'll get to that soon). Another fair choice, another good compromise between North & South, would be a mean-year length that's the arithmetic average of the March & September Equinox years. Some calendarists like the June Solstice tropical year, as a mean-year for a leapyear-rule. That's because the we're now only about a millennium into a roughly 10,000 year period during which the length of the June Solstice year will change remarkably little--not enough to cause any significant calendar-displacement with respect to the seasons.. To quote one calendarist: "Welcome to the 1st millennium of the Age of the June Solstice Year!"
