[Two years ago][old] (flippin’ heck it seems like only yesterday) I wrote about converting between Unix timestamps and Windows timestamps using Python. In that post I linked to my very simple implementation of a module that provides converting back and forth between the formats.

A few weeks ago I received an e-mail from Timothy Williams with changes to the my module so that it preserves the fractions of a second in the conversion. How sweet is that?!?!! Exclamation mark question mark exclamation mark cellida diaresis em-dash full stop king of punctuation.

It is fantastic that not only did someone find my code useful but also that they were generous enough to take the time to improve it and give the changes back to me. I love tasty, delicious free software and the people like Tim who make it tastier and more delicious.

So here is the new version of [filetimes.py incorporating Tim’s fixes][ft].

[old]: http://reliablybroken.com/b/2009/09/working-with-active-directory-filetime-values-in-python/
[ft]: http://reliablybroken.com/b/wp-content/filetimes.py

[How To Convert a UNIX time_t to a Win32 FILETIME or SYSTEMTIME][kb]:

> Under Win32 platforms, file times are maintained primarily in the form of
> a 64-bit FILETIME structure, which represents the number of 100-nanosecond
> intervals since January 1, 1601 UTC (coordinate universal time).

***UPDATED* New version with fixes by Tim Williams for preserving microseconds. See [here for details][updated].**

It just so happens that [Microsoft Active Directory][msad] uses the same 64-bit value to store some time values. For example [the `accountExpires` attribute][expires] is in this format. Linked below is a module for Python with utility functions for converting between [Python’s datetime instances][datetime] and Microsoft’s FILETIME values.

Very handy if you enjoy querying Active Directory for login accounts that are due to expire. And who wouldn’t enjoy that? On a Monday.

[Download filetimes.py module for converting between FILETIME and `datetime` objects.][filetimes] This code is released under a 2-clause BSD license.

Example usage:

>>> from filetimes import filetime_to_dt, dt_to_filetime, utc
>>> filetime_to_dt(116444736000000000)
datetime.datetime(1970, 1, 1, 0, 0)
>>> filetime_to_dt(128930364000000000)
datetime.datetime(2009, 7, 25, 23, 0)
>>> “%.0f” % dt_to_filetime(datetime(2009, 7, 25, 23, 0))
‘128930364000000000’
>>> dt_to_filetime(datetime(1970, 1, 1, 0, 0, tzinfo=utc))
116444736000000000L
>>> dt_to_filetime(datetime(1970, 1, 1, 0, 0))
116444736000000000L

I even remembered to write tests for once!

[kb]: http://support.microsoft.com/kb/167296
[msad]: http://www.microsoft.com/windowsserver2008/en/us/active-directory.aspx
[datetime]: http://docs.python.org/library/datetime.html
[expires]: http://msdn.microsoft.com/en-us/library/ms675098(VS.85).aspx
[filetimes]: /b/wp-content/filetimes.py
[updated]: http://reliablybroken.com/b/2011/09/free-software-ftw-updated-filetimes-py/