Parse date and time from string with time zone using Arrow

Question

I have

import arrow
s = '2015/12/1 19:00:00'
tz = 'Asia/Hong_Kong'

How can I parse this with Arrow such that I get an Arrow object with the time zone tz? The following defaults to UTC time.

In [30]: arrow.get(s, 'YYYY/M/D HH:mm:ss')
Out[30]: <Arrow [2015年12月01日T19:00:00+00:00]>

I know the .to function but that converts a time zone and but doesn't allow me to change to time zone.

• Bestasttung: In arrow doc i see that the constructor works like : "class arrow.arrow.Arrow(year, month, day, hour=0, minute=0, second=0, microsecond=0, tzinfo=None)". Is that enough for your problem? It actually returns an arrow object with you desired tz.

Answer 1

Try this:

arrow.get(s, 'YYYY/M/D HH:mm:ss', tzinfo=tz)

If you are also using dateutil, this works as well:

arrow.get(s, 'YYYY/M/D HH:mm:ss', tzinfo=dateutil.tz.gettz(tz))

So does this:

arrow.get(s, 'YYYY/M/D HH:mm:ss').replace(tzinfo=dateutil.tz.gettz(tz))

• mchangun: This works! Just out of curiosity, is it possible to do the same with pytz? I get some weird results: In [7]: arrow.get(s, 'YYYY/M/D HH:mm:ss').replace(tzinfo=pytz.timezone(tz)) Out[7]: <Arrow [2015年12月01日T19:00:00+07:37]>
• Matt Johnson-Pint: Not sure, but I think arrow is better aligned with dateutil than pytz.
• jfs: @mchangun: btw, I see that even after two years of development arrow still fails to convert utc datetime to a named timezone, convert utc time to local timezone, and round-trip timestamp -> named timezone -> utc
• jfs: @mchangun: "better" depends on your application. I use pytz but it might too low-level for most applications. Though all you need is to understand why pytz introduces localize(), normalize() methods, to use it correctly.
• Matt Johnson-Pint: @EricDuminil - Updated my answer. Thanks!

Answer 2

I'm not qualified yet to add a comment and would just like to share a bit simpler version of the answer with timezone str expression.

s = '2015/12/1 19:00:00'
tz = 'Asia/Hong_Kong'
arrow.get(s, 'YYYY/M/D HH:mm:ss').replace(tzinfo=tz)

or simply local timezone:

arrow.get(s, 'YYYY/M/D HH:mm:ss').replace(tzinfo='local')

or specified ISO-8601 style:

arrow.get(s, 'YYYY/M/D HH:mm:ss').replace(tzinfo='+08:00')

• Eric Duminil: I don't understand why arrow.get uses UTC as default, and not the local timezone.

Answer 3

Per the current documentation, you can also provide a default timezone for arrow.get(), e.g.:

s = '2015/12/1 19:00:00'
tz = 'Asia/Hong_Kong'
arrow.get(s, tzinfo=tz)

However, as of right now (version 0.12.1) there is a shortcoming where that doesn't work for string-based date parsing. Fortunately, this has been fixed, so the next release of Arrow will integrate this fix.

Answer 4

This is working for me as of 0.10.0:

import arrow
s = '2015/12/1 19:00:00'
tz = 'Asia/Hong_Kong'
arrow.get(s, 'YYYY/M/D HH:mm:ss', tzinfo=tz)
# <Arrow [2015年12月01日T19:00:00+08:00]>

However, arrow.get('2018-01-29 14:46', tzinfo='US/Central') (i.e. without the format string) ignores the tzinfo parameter.