Hi,
the examples you give work just fine on my computer
$Version (*"10.3.0 for Mac OS X x86 (64-bit) (October 9, 2015)"*)
I do seem to remember that I had a similar problem some time ago and rebuilding the PacletData would work.
RebuildPacletData[]
Cheers,
Marco
I tried the RebuildPacletData[], but that was no help.
In[339]:= $Version Out[339]= "10.3.0 for Microsoft Windows (64-bit) (October 9, 2015)"
Anyone from Wolfram who can comment on this?
I don't have 10.3. Did you try to use the date objects format for the dates?
https://reference.wolfram.com/language/ref/DateObject.html