When trying to make things work with the datetime module, most Python users have faced a point when we resort to guess-and-check until the errors go away. datetime is one of those APIs that seems ...

Learn how to work with date and time values using Python's datetime library, and how to avoid some of the gotchas and pitfalls of the datetime datatype. ... it isn’t an issue.

but the python datetime.time class doesn't seem to have defined arithmetic operators, nor does the datetime.timedelta. if there are methods for this, that's not obvious to me either: ...