DST (Daylight saving time) start late March walked past to the last weekend of September. But since 1996 we (the Netherlands and the rest of Europe) added a month under pressure from the British and the Irish to synchronize with the summertime in the United Kingdom. DST will run until the last weekend of October.
Now we use a double summer time which means that we are in the winter one hour and in summer two hours ahead of UTC (UTC is almost the same as Greenwich Mean Time (GMT)), because we are basically in the same time zone as Greenwich . However, the UK's summer time is one hour ahead of UTC.
So the question can be asked differently: Why (looks!) do British want to have their summer time another (extra?) month (till october)? Or DST starts there a month later?
I've questioned this also at earth science but they told me it belongs to politics