On Tue, Apr 16, 2013 at 4:55 PM, Bob Nnamtrop <bob.nnamt...@gmail.com> wrote: > I am curious if others have noticed an issue with datetime64 at the > beginning of 1970. First: > > In [144]: (np.datetime64('1970-01-01') - np.datetime64('1969-12-31')) > Out[144]: numpy.timedelta64(1,'D') > > OK this look fine, they are one day apart. But look at this: > > In [145]: (np.datetime64('1970-01-01 00') - np.datetime64('1969-12-31 00')) > Out[145]: numpy.timedelta64(31,'h') > > Hmmm, seems like there are 7 extra hours? Am I missing something? I don't > see this at any other year. This discontinuity makes it hard to use the > datetime64 object without special adjustment in ones code. I assume this a > bug?
Indeed, this looks like a bug, I can reproduce it on linux as well: In [1]: import numpy as np In [2]: np.datetime64('1970-01-01') - np.datetime64('1969-12-31') Out[2]: numpy.timedelta64(1,'D') In [3]: np.datetime64('1970-01-01 00') - np.datetime64('1969-12-31 00') Out[3]: numpy.timedelta64(31,'h') In [4]: np.__version__ Out[4]: '1.7.1' We need to look into the sources to see what is going on. Ondrej _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion