Definition
To express that time is on someone's side, or that they have time on their side, implies they are not under pressure to complete a task swiftly.
In this match, the young players on the team have a bright future ahead of them because time is on their side.
She can take more time to refine her artwork since time is on her side at the moment.
Although they couldn't finish the project on time, they don’t need to feel pressured because time is on their side.