It's about time
Meaning/Usage: When you want to express that you waited a long time. A synonym of this would be, "finally."
Explanation: When you wait for something, the time on a clock is the biggest factor.
It's about time.
It's about time. I waited two hours for you.
It's about time I got a chance to play.
A:
I've been waiting for 3 weeks to try out the new laptop. Isn't it my turn yet?
B:
Yes. It's your turn. I'll get it for you.
A:
It's about time.