Convert C# tick dates into a Python / readable date

ticks.py

# -*- coding: utf-8 -*-
"""
Purpose: Convert .NET ticks to formatted ISO8601 time
Author:  D Hohls < dhohls@csir.co.za>
"""
from __future__ import print_function
import datetime
import sys


def convert_dotnet_tick(ticks):
    """Convert .NET ticks to formatted ISO8601 time

    Args:
        ticks: integer
            i.e 100 nanosecond increments since 1/1/1 AD"""
    _date = datetime.datetime(1, 1, 1) + \
        datetime.timedelta(microseconds=ticks // 10)
    if _date.year < 1900:  # strftime() requires year >= 1900
        _date = _date.replace(year=_date.year + 1900)
    return _date.strftime("%Y-%m-%dT%H:%M:%S.%fZ")[:-3]

if __name__ == "__main__":
    try:
        print(convert_dotnet_tick(int(sys.argv[1])))
    except:
        print("Missing or invalid argument; use, e.g.:"
              " python ticks.py 636245666750411542")
        print("with result: %s " % convert_dotnet_tick( 636245666750411542))

Thanks!