All 28 member states would need to inform the European Commission of their choice ahead of the proposed switch, by April 2020. They would then coordinate with the bloc's executive so that their decisions do not disrupt the functioning of the single market.
Last year, the European Commission proposed abolishing the seasonal clock change after an EU-wide online poll showed overwhelming support. It has been accused, however, of rushing through the vote ahead of European Parliament elections in May.
Some 3 million of the 4.6 million survey responses came from Germany, leading to complaints the European Commission wanted to impose German will on the other states through sheer populism.
Russia switched to permanent summer time in 2011 in an attempt to improve citizens' well-being but shifted to permanent winter time three years later after public complaints.