Date/DateTime are documented as following the proleptic gregorian calendar, so negative values for the year imply BC/BCE era values.
On Mon, Aug 31, 2015 at 4:06 PM, Michael Francis <[email protected]> wrote: > it does seem that typemin and typemax of Date are rather large. It also > implies that a DateTime can not contain all possible Dates. Given the > following > > > > julia> typemin( DateTime ) > -146138511-01-01T00:00:00 > > > julia> typemax( DateTime ) > 146138512-12-31T23:59:59 > > > I was surprised to see negative values rather than the type being a > UInt64. But is somewhat makes sense as the types are wrappers on periods > for period math. So perhaps the issue is that typemin should be floored at > zero ? > > > On Monday, August 31, 2015 at 5:37:16 PM UTC-4, Jeffrey Sarnoff wrote: >> >> >> What is the utility of a date that predates the advent of time? >> >> On Friday, August 28, 2015 at 12:23:28 PM UTC-4, Michael Francis wrote: >>> >>> I agree except that people may expect yy-mm-dd to truncate, likely one >>> of the reasons for the ccyy-mm-dd strict form. Where yy is defined as the >>> two digit year. >>> >>> On Friday, August 28, 2015 at 11:51:14 AM UTC-4, Stefan Karpinski wrote: >>>> >>>> The safest option is probably to raise an error. >>>> >>>> On Fri, Aug 28, 2015 at 11:47 AM, Jacob Quinn <[email protected]> >>>> wrote: >>>> >>>>> Hmmmmm.......it's not entirely clear to me what we should do here. >>>>> >>>>> On the one hand, when you ask to have the typemax(Date) formatted, >>>>> it's currently doing what you asked, "formatting the year with 4 digits". >>>>> Because your year in this case is greater than 4 digits, that results in >>>>> truncation, which probably isn't what you want. But is it ok to give you >>>>> all the digits even though you only asked for 4? I'd appreciate any other >>>>> thoughts/input on this. >>>>> >>>>> I do think the Date/DateTime parsing/formatting code needs another >>>>> once over to polish it up, so any ideas on allowing more >>>>> flexibility/functionality would be appreciated. >>>>> >>>>> -Jacob >>>>> >>>>> >>>>> >>>>> On Friday, August 28, 2015 at 9:33:25 AM UTC-6, Michael Francis wrote: >>>>>> >>>>>> It seems that there is an issue with typemax of dates and string >>>>>> representation >>>>>> >>>>>> julia> using Dates >>>>>> >>>>>> >>>>>> julia> Dates.format(typemax( Date ),"yyyy-mm-dd" ) >>>>>> "1149-12-31" >>>>>> >>>>>> >>>>>> julia> typemax( Date ) >>>>>> 252522163911149-12-31 >>>>>> >>>>>> >>>>>> julia> Dates.format(typemax( Date ),"yyyyyyyyyyyyyyy-mm-dd" ) >>>>>> "252522163911149-12-31" >>>>>> >>>>>> This hidden truncation seems dangerous. Has anybody else seen this ? >>>>>> >>>>> >>>>
