问题
Under python on my machine I can run datetime.now() to get the local time. If I inspect time.daylight flag it is set to 1 because we are currently in July (hence daylight saving).
But if I run datetime.now() on Google App Engine (including the dev server) it doesn't account for daylight saving (british summer time) and returns the wrong time (13:47 instead of 14:47). If I inspect time.daylight in GAE it is set to 0.
How can I get the correct local time? Do I need to change the timezone on my app?
回答1:
Google App Engine's "time zone" is always set to UTC.
You can adjust to your local or desired time zone using a library like pytz.
Check out the following project on Google Code for an App Engine optimized version of pytz.
Google Code - gae-pytz
回答2:
AppEngine is a distributed system, whose servers can be located in different datacenters around the globe (afaik, currently EU and USA). Note that the python code you are running runs on the server not in the browser, so you'll never get the client's time. To get clients' time you'll need to use JavaScript and then send it to server.
GAE servers' timezone is always set to UTC. Since UTC is in summer time one hour off from UK time, you are getting an hour difference.
See this blog series for time handling on GAE: http://www.learningtechnicalstuff.com/2010/01/supporting-timezones-in-google-app.html
回答3:
I've been able to get this working:
import pytz
import datetime
tz = pytz.timezone('Europe/London')
print datetime.datetime.now(tz)
It appears Google App Engine already imports a few modules by default, including pytz and datetime, so perhaps there is no need to explicitly import them.
来源：https://stackoverflow.com/questions/17908994/how-to-get-current-uk-time-in-google-app-engine