For the Poll, the Jeans proposal would be to introduce manually: [2024-02-04 12:00 @America/Vancouver] And org to convert it into: [2024-02-04 12:00 @-08,America/Vancouver] ?
Ihor's would add the option to get warnings, in case tzdata changes, when that timestamp is generated? [2024-02-04 12:00 @-08,!America/Vancouver] ? Feb 5, 2023 13:12:25 Jean Louis <bugs@gnu.support>: > * Ihor Radchenko <yanta...@posteo.net> [2023-02-05 13:45]: >> [2024-02-04 12:00 @-08,America/Vancouver] will use fixed -8 offset > > What does that mean practically? Provide example for better > understanding. > > - The UTC offset is not certain to remain fixed in the future. > > - If you do not have the time of creation of the timestamp above, you > cannot know with certainty what was the offset in past, to calculate > new UTC offset in case it changed > > - As not even time zone is certain to remain in existence in future, > you will need to use time zone, in order to derive that future UTC > offset correctly. As it could change in mean time. > > What is meaning of "fixed -8 offset"? > >> [2024-02-04 12:00 @-08] will also use fixed -8 offset > > That type of timestamp does not clearly show the time zone, that one > may only be understood as timestamp with UTC offset. UTC time may be > derived from such timestamp. That offset should remain fixed, as there > is no time zone associated. It is UTC time represented with offset. > >> [2024-02-04 12:00 @America/Vancouver] will use @America/Vancouver time >> zone, as it is be defined in you OS time zone database. > > If you do not keep UTC offset, you will miss changes in future and > generate errors. > >> [2024-02-04 12:00 @-08,!America/Vancouver] (note "!") will use fixed -8 >> offset, but also calculate America/Vancouver time from TZ database, >> compare it with the time coming from -8 offset, and warn you if there is >> inconsistency. > > The UTC offset is the log what was the UTC offset at the time point > when timestamp was created, as future UTC offset cannot be known. > > Making it "fixed" does not fix it in real time, you are then > introducing something new than what other programs do with time. > > I do not think that you need "!", you are creating work not necessary > for users. > > If users wish to get some warnings, let them customize single option. > > Not timestamp by timestamp. > > -- > Jean > > Take action in Free Software Foundation campaigns: > https://www.fsf.org/campaigns > > In support of Richard M. Stallman > https://stallmansupport.org/
