Re: [O] Time-zone in dates

2015-07-08 Thread Don Armstrong
On Tue, 07 Jul 2015, Russell Adams wrote: On Wed, Jul 01, 2015 at 12:22:43PM +0100, Eric S Fraga wrote: I particularly like the single event (a flight) that requires more than one time zone to make sense. My diary is chock full of cases where it looks like a flight out somewhere takes 2

Re: [O] Time-zone in dates

2015-07-08 Thread Russell Adams
On Wed, Jul 08, 2015 at 10:59:54AM -0500, Don Armstrong wrote: The relative timezone of the observer is important, though, because that's how you enter the information, and it's often the most logical way to display the information. If you just store UTC there's no way to regenerate that. I'd

Re: [O] Time-zone in dates

2015-07-08 Thread Eric S Fraga
On Wednesday, 8 Jul 2015 at 11:16, Russell Adams wrote: [...] Then would you store the time in UTC only, or support a full timestamp that included timezone? Finally when being displayed they can use the user's $TZ by default, and maybe a suffix of @ TZ inside the date syntax? The ideal

Re: [O] Time-zone in dates

2015-07-08 Thread Titus von der Malsburg
On 2015-07-08 Wed 09:40, Eric S Fraga wrote: On Wednesday, 8 Jul 2015 at 11:16, Russell Adams wrote: [...] Then would you store the time in UTC only, or support a full timestamp that included timezone? Finally when being displayed they can use the user's $TZ by default, and maybe a

Re: [O] Time-zone in dates

2015-07-07 Thread Don Armstrong
On Wed, 01 Jul 2015, Michael Brand wrote: On Wed, Jul 1, 2015 at 8:27 AM, Eric S Fraga e.fr...@ucl.ac.uk wrote: On Tuesday, 30 Jun 2015 at 11:08, Nick Dokos wrote: In what way are you losing information? Sorry, should have been clear: the time zone information itself. By reducing to

Re: [O] Time-zone in dates

2015-07-07 Thread Russell Adams
On Wed, Jul 01, 2015 at 12:22:43PM +0100, Eric S Fraga wrote: Michael, thanks for some brilliant use cases! I particularly like the single event (a flight) that requires more than one time zone to make sense. My diary is chock full of cases where it looks like a flight out somewhere takes

Re: [O] Time-zone in dates

2015-07-01 Thread Michael Brand
Hi all On Wed, Jul 1, 2015 at 8:27 AM, Eric S Fraga e.fr...@ucl.ac.uk wrote: On Tuesday, 30 Jun 2015 at 11:08, Nick Dokos wrote: In what way are you losing information? Sorry, should have been clear: the time zone information itself. By reducing to UTC, you lose one bit of information.

Re: [O] Time-zone in dates

2015-07-01 Thread Eric S Fraga
Michael, thanks for some brilliant use cases! I particularly like the single event (a flight) that requires more than one time zone to make sense. My diary is chock full of cases where it looks like a flight out somewhere takes 2 hours but coming back takes 11! (strong winds ;-) -- : Eric S

Re: [O] Time-zone in dates

2015-07-01 Thread Nick Dokos
Eric S Fraga e.fr...@ucl.ac.uk writes: On Tuesday, 30 Jun 2015 at 11:08, Nick Dokos wrote: Eric S Fraga e.fr...@ucl.ac.uk writes: On Monday, 29 Jun 2015 at 21:17, Nick Dokos wrote: The only reliable way of doing that is to use UTC as the internal representation and translate to/from local

Re: [O] Time-zone in dates

2015-07-01 Thread Left Right
My initial case was very similar to the one Michael described in the telepresence example, except that in my case, I need to assign shifts to people living in different timezones. I.e. I need to make sure that a shift assigned to someone in Illinois will end at the same time when the shift of

Re: [O] Time-zone in dates

2015-07-01 Thread Eric S Fraga
On Tuesday, 30 Jun 2015 at 11:08, Nick Dokos wrote: Eric S Fraga e.fr...@ucl.ac.uk writes: On Monday, 29 Jun 2015 at 21:17, Nick Dokos wrote: The only reliable way of doing that is to use UTC as the internal representation and translate to/from local time on external display/input *only*.

Re: [O] Time-zone in dates

2015-06-30 Thread Eric S Fraga
On Monday, 29 Jun 2015 at 21:17, Nick Dokos wrote: The only reliable way of doing that is to use UTC as the internal representation and translate to/from local time on external display/input *only*. In the case of org mode, the internal representation is user-visible, so that can cause

Re: [O] Time-zone in dates

2015-06-30 Thread Nick Dokos
Eric S Fraga e.fr...@ucl.ac.uk writes: On Monday, 29 Jun 2015 at 21:17, Nick Dokos wrote: The only reliable way of doing that is to use UTC as the internal representation and translate to/from local time on external display/input *only*. In the case of org mode, the internal representation

Re: [O] Time-zone in dates

2015-06-29 Thread Eric S Fraga
On Friday, 26 Jun 2015 at 21:57, franc...@avalenn.eu wrote: [...] It is really simpler programmatically to deal with time offsets instead. The downside is that you cannot manage DST and other similar peculiarities but the API is much simpler to write. Time offsets are not sufficient. My

Re: [O] Time-zone in dates

2015-06-29 Thread Nick Dokos
Eric S Fraga e.fr...@ucl.ac.uk writes: On Friday, 26 Jun 2015 at 21:57, franc...@avalenn.eu wrote: [...] It is really simpler programmatically to deal with time offsets instead. The downside is that you cannot manage DST and other similar peculiarities but the API is much simpler to write.

Re: [O] Time-zone in dates

2015-06-26 Thread J. David Boyd
Eric S Fraga e.fr...@ucl.ac.uk writes: On Friday, 26 Jun 2015 at 16:40, Oleg Sivokon wrote: Hello, list. I was looking for a way to add time-zone to the date recrod, something like: 2015-07-05 Sun 20:00 GMT+0. I was told that it's very likely that the functionality isn't there, so I wonder

Re: [O] Time-zone in dates

2015-06-26 Thread Eric S Fraga
On Friday, 26 Jun 2015 at 16:40, Oleg Sivokon wrote: Hello, list. I was looking for a way to add time-zone to the date recrod, something like: 2015-07-05 Sun 20:00 GMT+0. I was told that it's very likely that the functionality isn't there, so I wonder if it's really so, and if indeed so,

Re: [O] Time-zone in dates

2015-06-26 Thread Left Right
On Fri, Jun 26, 2015 at 5:12 PM, Eric S Fraga e.fr...@ucl.ac.uk wrote: Somebody to program the functionality in but this is a major challenge as time stamps are a fundamental building block of org and it would likely need to be upwards compatible... -- : Eric S Fraga (0xFFFCF67D), Emacs

Re: [O] Time-zone in dates

2015-06-26 Thread Eric S Fraga
On Friday, 26 Jun 2015 at 10:38, J. David Boyd wrote: [...] I can see that being a real pain. The simple way would 'just' be to convert everything to UTC in the background for comparison. Having spent a year essentially commuting between Australia and the UK a couple of years ago, I can tell

Re: [O] Time-zone in dates

2015-06-26 Thread Nicolas Goaziou
Hello, Eric S Fraga e.fr...@ucl.ac.uk writes: In practice, I do not miss having time zone information in org. Time zone information is interesting when users of different areas are exchanging Org documents. I think it would be useful to have: - a keyword to specify time zone per document.

Re: [O] Time-zone in dates

2015-06-26 Thread francois
Hello, On Fri, Jun 26, 2015 at 09:20:00PM +0200, Nicolas Goaziou wrote: Time zone information is interesting when users of different areas are exchanging Org documents. I think it would be useful to have: - a keyword to specify time zone per document. This time zone would apply to

Re: [O] Time-zone in dates

2015-06-26 Thread Nicolas Goaziou
Hello, franc...@avalenn.eu writes: Timezones are strange beasts to deal with. True. It is really simpler programmatically to deal with time offsets instead. The downside is that you cannot manage DST and other similar peculiarities but the API is much simpler to write. However, time