human
millisecond utc to datetime datetime.
assistant
Here is a Python function to millisecond utc to datetime datetime

import datetime

def _ms_to_datetime(ms):
    """Convert a millisecond utc to datetime datetime"""
    return datetime.datetime.utcfromtimestamp(ms)

# Enter the millisecond
ms = 1234567890

# Calling the function
datetime_ms = _ms_to_datetime(ms)

# Printing the datetime
print(datetime_ms)

#Example Output
# 2009-02-13 23:31:30

#Remember to inspect code for bugs.