run2-timezone-dst

name	run2_timezone-dst
description	Convert US time zones to the calendar's local timezone, correctly handling Daylight Saving Time for dates in March through November.

Timezone Conversion with DST Awareness

DST in the US

• Starts: 2nd Sunday of March at 2:00 AM → clocks spring forward 1 hour
• Ends: 1st Sunday of November at 2:00 AM → clocks fall back 1 hour
• During DST: PST→PDT, MST→MDT, CST→CDT, EST→EDT

March 9, 2026 Check

• DST started: Sunday, March 8, 2026 at 2:00 AM
• March 9 is AFTER the DST change → all US zones are in summer (DT) variants

Offset Table for March 9, 2026

Sender says	Actual zone	UTC offset	vs EDT (calendar)
PST	PDT	UTC-7	+3 hours
MST	MDT	UTC-6	+2 hours
CST	CDT	UTC-5	+1 hour
EST/ET	EDT	UTC-4	same

Conversion Examples for March 9, 2026

Sender says "1:00 PM PST":
  → PDT (UTC-7) → EDT (UTC-4) → add 3 hours
  → 4:00 PM EDT (Eastern)

Sender says "5:00 PM PST":
  → 8:00 PM EDT (Eastern)

Python (pytz)

from datetime import datetime
import pytz

pacific = pytz.timezone('America/Los_Angeles')  # handles PDT automatically
eastern = pytz.timezone('America/New_York')     # handles EDT automatically

dt = pacific.localize(datetime(2026, 3, 9, 13, 0))  # "1 PM PST"
dt_et = dt.astimezone(eastern)
print(dt_et.strftime('%I:%M %p'))  # 04:00 PM

Key Rule

When an email says "PST" but the date is in March/April–October/November, assume PDT. The +3 hour offset to Eastern still applies (PDT to EDT both shift by 1 hour each).