Converts a potentially timezone-aware datetime to be a naive UTC datetime

def convert_to_timezone_naive(time_to_freeze):
    """
    Converts a potentially timezone-aware datetime to be a naive UTC datetime
    """
    if time_to_freeze.tzinfo:
        time_to_freeze -= time_to_freeze.utcoffset()
        time_to_freeze = time_to_freeze.replace(tzinfo=None)
    return time_to_freeze