Noon in Which Timezone? — Python Bug Hunt

Briefing

Inspired by the countless "meeting at noon" disasters of naive timestamp handling. Feeds send wall-clock times WITH their UTC offset — and the parser throws the offset away, so 12:00 in Mumbai and 12:00 in New York collide.

clocktime.py normalises "HH:MM±OH:OM" to minutes-since-midnight UTC.

Bug report

BUG-TZ-NAIVE · Priority: High · Reported by: scheduling

to_utc_minutes(stamp):

• "12:00+05:30" -> 390 (12:00 IST is 06:30 UTC)
• "09:00-04:00" -> 780 (09:00 EDT is 13:00 UTC)
• wrap into [0, 1440)

Observed: the offset part is ignored entirely.

Logs

[sched] "12:00+05:30" == "12:00-04:00" -> double-booked room

The code as shipped

src/time/clocktime.py (editable)

# Normalises "HH:MM+OH:OM" (or -OH:OM) to minutes since midnight UTC.

def to_utc_minutes(stamp):
    hh = int(stamp[0:2])
    mm = int(stamp[3:5])
    return hh * 60 + mm