Here is my example:
import datetime
from pytz import timezone
EST_TZ = timezone('US/Eastern')
t1 = datetime.datetime.now(EST_TZ)
t2 = datetime.datetime.combine(datetime.datetime.now(EST_TZ).date(), datetime.time(6, 0, 0)).replace(tzinfo=EST_TZ)
(t2-t1).total_seconds()
t1
is roughly datetime.datetime(2023, 3, 15, 5, 54, 31, 438854, tzinfo=<DstTzInfo 'US/Eastern' EDT-1 day, 20:00:00 DST>)
t2
is roughly datetime.datetime(2023, 3, 15, 6, 0, tzinfo=<DstTzInfo 'US/Eastern' LMT-1 day, 19:04:00 STD>)
by difference t2-t1 = 3688.561146
has an extra hour due to day light savings (my guess).
Is there an easy fix?