The EU was supposed to end the system (countries would choose to keep either their summer or winter time zones) but it seems to have become blocked. Just the UK

The EU was supposed to end the system (countries would choose to keep either their summer or winter time zones) but it seems to have become blocked. Just the UK having left with no political desire to do anything that looks like an EU idea, combined with Irish opposition to different zones for the Republic of Ireland and Northern Ireland may stymy it indefinitely. In the meantime, all EU countries observe a summer time that starts and ends on the same day across the EU.