(it's) about time
An expression used to emphasize that something should have occurred a long time ago. Well, it's about time you got here—I've been waiting for an hour! It's about time that high schools taught their students about basic banking and finance. A: "He finally moved out of his parents' house." B: "About time! He's 40 years old."
it is high time
It is the appropriate time (that something happen); it is long overdue (that something happen). Thank you for a lovely meal, but it's high time for us to start heading home. It is high time that someone gives him the punishment he deserves!
it's high time
Rur. it is about the right time for something. It's high time we were leaving. It's high time you started thinking about saving for your old age.
it's about time
Also, it's high time. See about time; high time.
it’s ˌhigh/aˌbout ˈtime (that)...
(spoken) used for saying that something should be done or happen immediately or very soon: It’s high time that this room was properly cleaned!So you’ve started work! It’s about time! (= you should have started a long time ago).