-
2022.05.12 18:53 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Kemp Watson
- 2022.05.12 18:59 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Simon (Vsevolod) Ilyushchenko
-
2022.05.12 20:09 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Simon (Vsevolod) Ilyushchenko
-
2022.05.12 21:50 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Even Rouault
-
2022.05.12 21:58 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Simon (Vsevolod) Ilyushchenko
-
2022.05.12 22:15 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Even Rouault
- 2022.05.12 22:29 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Kemp Watson
- 2022.05.12 23:34 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Simon (Vsevolod) Ilyushchenko
- 2022.05.13 00:35 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Leonard Rosenthol
-
2022.05.12 22:15 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Even Rouault
-
2022.05.12 21:58 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Simon (Vsevolod) Ilyushchenko
- 2022.05.13 00:18 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Julian H. Stacey
-
2022.05.12 21:50 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Even Rouault
2022.05.13 00:18 "Re: [Tiff] best tiff tag names for start and end datetimes?", by Julian H. Stacey
1. Bob: The reason I'd like to have the option of timezones is that modern timestrings like ISO8601 often have them, so using Z to indicate UTC (which is indeed the majority of our timestamps) would both handle the common case and allow the possibility of using other timezones.
When I last read bits of 8601, I can't recall it allowing textual names of TZ, I hope not. https://en.wikipedia.org/wiki/ISO_8601#Usage
Best avoid any TZ scheme that allows textual names for local timezones, Insist on numeric only. I once wrote C to make sense of dates in mail headers,
http://www.berklix.com/~jhs/src/bsd/jhs/bin/public/mailname/mailname.c
It was a pain, needing extensions as I discovered more acronyms.
Then I wondered about the world of politicians who muck around changing whether & when they will change dates of summer / winter shifts this year, or go double summer time, or suppress summer time & stick to winter / solar, or lock permanently on a 1 hour summer offset, & that for every nation on earth, & regions within some contries, & eg I recall Australia used to have 3 x 40 min shifts across the Nullabor.
All the ever changing timezone complexity is dealt with eg in FreeBSD in special libraries, & most likely different libraries on other BSD & Linuses, so a porting hastle.
Best avoid porting or maintenace work by insisting on numeric only date strings (+ 'Z' & '-' & ':' ).
Simon (Vsevolod) Ilyushchenko wrote:
> Unix type systems (and those using NTP) have a system clock which is
> on UTC time.
Long ago I had a BSD 4.2 binary kernel whose native time was PDT=GMT-7
http://www.berklix.com/~jhs/symmetric/
I think numerous really old Unix binary kernels did. It would seem risky assuming all modern commercial binary kernels use UTC? even if the modern PD src/ BSD & Linux may.
Cheers,
Julian Stacey http://berklix.com/jhs/ http://stolenVotes.uk
Arm Ukraine, Zap killer Putin, grain & fuel loss hits poorest.