in advance
idiomPart ofadvance
in advance — idiom
1. before something happens or before the usual time, often so that you can be read
1.idiom
Definition
before something happens or before the usual time, often so that you can be ready or so that other people know what to expect.
Example
Nadia booked the train tickets two weeks in advance to get a cheaper price.
Please let Rashida know in advance if you cannot come to the dinner.