[Python-Dev] datetime module enhancements (original) (raw)

BJörn Lindqvist bjourne at gmail.com
Fri Mar 9 18:51:18 CET 2007

On 3/9/07, Guido van Rossum <guido at python.org> wrote:

On 3/9/07, BJörn Lindqvist <bjourne at gmail.com> wrote: > On 3/9/07, Guido van Rossum <guido at python.org> wrote: > > On 3/9/07, skip at pobox.com <skip at pobox.com> wrote: > > > The range of datetime objects far exceeds that of the current Unix > > > timestamp. Given that the range of current (32-bit) Unix timestamps is > > > approximately 1970 to 2038, What would the output of this be? > > > > > > dt = datetime.datetime(3000, 1, 1, 0, 0, 0) > > > print dt.totimestamp() > > > dt = datetime.datetime(1900, 1, 1, 0, 0, 0) > > > print dt.totimestamp() > > > > If you extend the range to 64 bits there's no problem: the first > > should print 32503680000, the second -2208988800. > > I think it should be a ValueError, given that the programmer is very > likely to further use the returned timestamp to for example insert > stuff in a database. Unix timestamps are not unambiguously defined for > any years other than 1970 to 2038 imho.

But they will be. And they already are on some platforms. The database should raise an OverflowError if a timestamp is out of range, but it would be unpythonic to limit those outcomes to 32 bits.

Then I guess datetime.fromtimestamp() also should be fixed?:

datetime.fromtimestamp(-1) Traceback (most recent call last): File "", line 1, in ValueError: timestamp out of range for platform localtime()/gmtime() function datetime.fromtimestamp(-0.5) Traceback (most recent call last): File "", line 1, in ValueError: microsecond must be in 0..999999 datetime.fromtimestamp(9999999999) Traceback (most recent call last): File "", line 1, in ValueError: timestamp out of range for platform time_t

Would be nice if datetime.fromtimestamp(dt.totimestamp()) == dt worked for all datetimes.

-- mvh Björn

More information about the Python-Dev mailing list