问题
i am confused about timezone and countrys at time-changes. Carlifornia changes the time at 10am, NewYork at 7am.
How can i programmatically get informations when the time will change next in California?
回答1:
To find out DST transitions, you could access Olson timezone database e.g., to find out the time of the next DST transition, in Python:
#!/usr/bin/env python
from bisect import bisect
from datetime import datetime
import pytz # $ pip install pytz
def next_dst(tz):
dst_transitions = getattr(tz, '_utc_transition_times', [])
index = bisect(dst_transitions, datetime.utcnow())
if 0 <= index < len(dst_transitions):
return dst_transitions[index].replace(tzinfo=pytz.utc).astimezone(tz)
e.g., in Los Angeles:
dt = next_dst(pytz.timezone('America/Los_Angeles'))
print(dt.strftime('%Y-%m-%d %H:%M:%S %Z%z'))
Output:
2014-11-02 01:00:00 PST-0800
or in a local timezone:
from tzlocal import get_localzone # $ pip install tzlocal
dt = next_dst(get_localzone())
if dt is not None:
print(dt.strftime('%Y-%m-%d %H:%M:%S %Z%z'))
else:
print("no future DST transitions")
来源：https://stackoverflow.com/questions/23045720/programmatically-get-the-time-at-clock-change