クライアント (モバイル) の真夜中のタイムスタンプを取得するには、クライアントのタイムゾーンを知る必要があります。
from datetime import datetime
import pytz # pip install pytz
fmt = '%Y-%m-%d %H:%M:%S %Z%z'
tz = pytz.timezone("America/New_York") # supply client's timezone here
# Get correct date for the midnight using given timezone.
# due to we are interested only in midnight we can:
# 1. ignore ambiguity when local time repeats itself during DST change e.g.,
# 2012-04-01 02:30:00 EST+1100 and
# 2012-04-01 02:30:00 EST+1000
# otherwise we should have started with UTC time
# 2. rely on .now(tz) to choose timezone correctly (dst/no dst)
now = datetime.now(tz)
print(now.strftime(fmt))
# Get midnight in the correct timezone (taking into account DST)
midnight = tz.localize(now.replace(hour=0, minute=0, second=0, microsecond=0, tzinfo=None),
is_dst=None)
print(midnight.strftime(fmt))
# Convert to UTC (no need to call `tz.normalize()` due to UTC has no DST transitions)
dt = midnight.astimezone(pytz.utc)
print(dt.strftime(fmt))
# Get POSIX timestamp
print((dt - datetime(1970,1,1, tzinfo=pytz.utc)).total_seconds())
出力
2012-08-09 08:46:29 EDT-0400
2012-08-09 00:00:00 EDT-0400
2012-08-09 04:00:00 UTC+0000
1344484800.0
注:私のマシンでは、@ phihagの回答は1344470400.0
上記とは異なります(私のマシンはニューヨークにありません)。