Time is on their side - Idioms by The Free Dictionary
time is on (one's) side (redirected from time is on their side)
time is on (one's) side
One has the advantage of having a lot of time to do something or wait for something; the amount of time available is an asset. The good news is that time is on our side. We still have three weeks until we have to submit our proposal.
time is on somebody’s ˈside (also have time on your side) somebody has enough time to do something; the more that time passes, the more somebody will be helped: Although she failed the exam, time is on her side; she is young enough to take it again next year. ♢ The longer we wait to sell the house, the more it will be worth, so we’ve got time on our side.