I would like to voice my opposition the totimestamp method.

Representing time as a float is a really bad idea (originated at 
Microsoft as I have heard).  In addition to the usual numeric problems 
when dealing with the floating point, the resolution of the floating 
point timestamp varies from year to year making it impossible to 
represent high resolution historical data.

In my opinion both time.time() returning float and 
datetime.fromtimestamp() taking a float are both design mistakes and 
adding totimestamp that produces a float will further promote a bad 
practice.

I would not mind integer based to/from timestamp methods taking and 
producing seconds or even (second, microsecond) tuples, but I don't 
think changing fromtimestamp behavior is an option.