time is on someone's side idiom (also have time on your side)
（某人）有充裕的时间
If you say that time is on your side, or that you have time on your side, you mean that you do not have to do quickly whatever it is that you want or have to do.
We don't have to make a final decision till next week, so time is on our side. 下星期之前我们不必作出最后的决定，因此我们有充裕的时间。