#!/usr/bin/env python3

from datetime import datetime, tzinfo, timedelta


class TZMadrid(tzinfo):
    def utcoffset(self, dt):
        return timedelta(hours=1) + self.dst(dt)

    def dst(self, dt):
        dston = datetime.date(dt.year, 4, 1)
        dstoff = datetime.date(dt.year, 10, 27)
        # Code to set dston and dstoff to the time zone's DST
        # transition times based on the input dt.year, and expressed
        # in standard local time.

        if dston <= dt.replace(tzinfo=None) < dstoff:
            return timedelta(hours=1)
        else:
            return timedelta(0)