From Longman Dictionary of Contemporary Englishan early nightan early nightEARLYSLEEPif you have an early night, you go to bed earlier than usual OPP a late nighthave/get an early night I think I’ll get an early night. → early
Examples from the Corpus
have/get an early night• Below once more, with everything as secure as she could make it, she decided she might as well have an early night.• But, if tonight you find yourself yawning at 9.30, why not have an early night?• Cancel any evening plans - have an early night.• I should have left you to fix your light snack and have an early night.• Maybe she would skip dinner and simply go to her cabin, unpack her things and get an early night.• Then I just felt so tired I thought I'd have an early night.• You should have an early night, but I don't suppose you will sleep. 