it's high/about time...

(it's) (a)bout time

An expression used to emphasize that something should have occurred a long time ago. Well, about time you got here—I've been waiting for over an hour! It's about time that high schools taught their students about basic banking and finance. A: "Tom finally moved out of his parents' house." B: "Bout time! He's 40 years old."
See also: time

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!
See also: high, time
Farlex Dictionary of Idioms.

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.
See also: high, time
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

it's about time

Also, it's high time. See about time; high time.
See also: time
The American Heritage® Dictionary of Idioms by Christine Ammer.

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).
See also: high
Farlex Partner Idioms Dictionary
See also:
  • (it's) (a)bout time
  • about time
  • about time too
  • any time
  • anytime
  • any time means no time
  • any old time
  • at all hours
  • at all hours (of the day and night)
  • (it's) time to run