The European Parliament has backed a review of daylight saving time, a move that could stop clocks switching back and forward between winter and summer.
EU lawmakers called for the European Commission to launch a "full evaluation" of the current system and come up with new plans, if necessary.
Supporters of the current system say it saves energy and reduces traffic accidents.
But critics argue it can cause long-term health problems.
Current EU law stipulates a common date in spring and autumn on which clocks must be put forward and back by one hour in all 28 member states.
The idea is that it provides extra evening daylight in summer and extra morning daylight in winter.
But opinions remain divided all over the world about the benefits of the system.