Date Format incorrect using strptime [duplicate]

Question

Possible Duplicate:
Python strptime() and timezones?

'Saturday, December 22, 2012 1:22:24 PM EST' does not match format '%A, %B %d, %Y %I:%M:%S %p %Z'

Maybe I'm missing something but can anyone spot why this doesn't validate properly?

Answer 1

The strptime() function cannot handle %Z timezone parsing very well. Only UTC and GMT are really supported, and the current value of time.tzname. See the strptime documenation:

Support for the %Z directive is based on the values contained in tzname and whether daylight is true. Because of this, it is platform-specific except for recognizing UTC and GMT which are always known (and are considered to be non-daylight savings timezones).

Removing the EST part of your input and the %Z part of your format string makes things work:

>>> import time
>>> time.strptime('Saturday, December 22, 2012 1:22:24 PM EST', '%A, %B %d, %Y %I:%M:%S %p %Z')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/_strptime.py", line 454, in _strptime_time
    return _strptime(data_string, format)[0]
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/_strptime.py", line 325, in _strptime
    (data_string, format))
ValueError: time data 'Saturday, December 22, 2012 1:22:24 PM EST' does not match format '%A, %B %d, %Y %I:%M:%S %p %Z'
>>> time.strptime('Saturday, December 22, 2012 1:22:24 PM', '%A, %B %d, %Y %I:%M:%S %p')
time.struct_time(tm_year=2012, tm_mon=12, tm_mday=22, tm_hour=13, tm_min=22, tm_sec=24, tm_wday=5, tm_yday=357, tm_isdst=-1)

or replacing the timezone EST with GMT:

>>> time.strptime('Saturday, December 22, 2012 1:22:24 PM GMT', '%A, %B %d, %Y %I:%M:%S %p %Z')
time.struct_time(tm_year=2012, tm_mon=12, tm_mday=22, tm_hour=13, tm_min=22, tm_sec=24, tm_wday=5, tm_yday=357, tm_isdst=0)

To parse strings with a timezone other than time.tzname, GMT or UTC, use a different date parsing library. The dateutil library has an excellent parse function that handles timezones properly:

>>> from dateutil.parser import parse
>>> parse('Saturday, December 22, 2012 1:22:24 PM EST', tzinfos={'EST': -18000})
datetime.datetime(2012, 12, 22, 13, 22, 24, tzinfo=tzoffset(u'EST', -18000))

When using dateutil.parser.parse() you do have to provide your own timezone offsets for your format though.