def isAmbiguous(dt):
    """Helper function to check if a datetime is ambiguous. This is necessary
    because GridLAB-D uses MySQL's timestamp datatype, which has no timezone
    or DST information. This function strips off a datetime object's tzinfo,
    then checks if the time would be ambiguous without that information.
    """
    dtNaive = dt.replace(tzinfo=None)
    return dt.tzinfo.is_ambiguous(dtNaive)