UTC offset from POSIX rule about zig-tzif HOT 4 CLOSED

Ohhh, that is confusing. I would to happy to merge a pull request if you have the time.

from zig-tzif.

I've made a draft here: #6

Turns out this is some rabbit hole to go down... Before I can proceed with this, I'll have to get a clear understanding of your concept :)

• The method PosixTZ.offset() - is it supposed to take Unix time in seconds and return the corresponding UTC offset of given time zone? Is that correct?
• Same goes for TimeZone.localTimeFromUTC() I suppose? (--> Unix time + corresponding UTC offset)

from zig-tzif.

• The method PosixTZ.offset() - is it supposed to take Unix time in seconds and return the corresponding UTC offset of given time zone? Is that correct?

Yep, that's correct. It takes a unix timestamp in seconds and returns what the UTC offset is at that time based on the rules around Daylight Saving Time.

• Same goes for TimeZone.localTimeFromUTC() I suppose? (--> Unix time + corresponding UTC offset)

And this is also correct, if I understand what you're saying. It takes a Unix timestamp in UTC and converts it into a timestamp in the given timezone.

from zig-tzif.

right, I think the missing part was subtracting the offset, which you have now added here

            const start_dst = range.start.toSecs(utc_year) - this.std_offset;
            const end_dst = range.end.toSecs(utc_year) - this.dst_offset;

from zig-tzif.