“It's about time!”

There was a broken light on the first floor of your apartment building that hadn't been fixed for two weeks. A neighbor tells you that it's been fixed, and you're happy because it was annoying you. You say:

It's about time!

It's about time!

You say "It's about time!" when something finally happens that you think should have happened a long time ago. When you use this, you sound like you're annoyed by how long something took. Here's an example:

A: Pete finally sent me the files I've been waiting for.

B: It's about time!

When you pronounce this, put stress on both "about" and "time":

It's about time!

People don't usually use this phrase in written English.