def _offset(value):
    """Parse timezone to offset in seconds.

    Args:
        value: A timezone in the '+0000' format. An integer would also work.

    Returns:
        The timezone offset from GMT in seconds as an integer.
    """
    o = int(value)
    if o == 0:
        return 0
    a = abs(o)
    s = a * 36 + a % 100 * 24
    return o // a * s
