Calculate difference between two timestamps

time-diff.py

#! /usr/bin/env python

"""Calculate time difference between two timestamps

First argument is the "from" time and second is the "to" time. Format should
be anything that works with `datetime.fromisoformat`
(https://docs.python.org/3/library/datetime.html#datetime.datetime.fromisoformat).
"""

from datetime import datetime
import sys

from_time = datetime.fromisoformat(sys.argv[1])
to_time = datetime.fromisoformat(sys.argv[2])
print(to_time - from_time)