[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Daylight Saving Time
- To: common-lisp@SU-AI.ARPA
- Subject: Daylight Saving Time
- From: GREEK@DEC-MARLBORO.ARPA
- Date: Fri 14 Sep 84 14:56:44-EDT
I hate to beat a horse which everyone wishes were dead, but:
What should DECODE-UNIVERSAL-TIME do about daylight saving time?
Clearly, ENCODE-UNIVERSAL-TIME takes it into accout, if appropriate, when
normalizing to GMT. When decoding, however, who knows if the original time
was on daylight saving time? And if decoding into a different time zone, who
knows if that zone is on daylight saving time? At the very least,
DECODE-UNIVERSAL-TIME has no business returning daylight-saving-time-p.
In VAX LISP, we take daylight saving time in account when decoding into
the local time zone, and in no other case. This means that if a local
time is encoded and then decoded in California, it's off by one hour.
I think our algorithm is bogus, but I'm not sure what to do.