import sys
import dateutil.parser

def errx(msg):
    sys.exit(f'quarg: {msg}')

def parse_isodate(date):
    try:
        parsed = dateutil.parser.isoparse(date)
    except ValueError as err:
        errx(f'isoparse: invalid date format \'{date}\', {err}')
    except OverflowError as err:
        errx(f'isoparse: date overflows: \'{date}\'')

    # If no offset is given, assume local time
    if parsed.tzinfo is None:
        parsed = parsed.astimezone()

    return parsed