What is the meaning of high time?

Answer 1

The usual meaning is that the thing referred to is past due and payable. Another way to think of it is that the time is 'critical'. I might say to my son "It's high time you get your chores done, John", implying that if they don't get done right now there will be consequences.

'High time' derives from the allusion to the warmest time of day - when the sun is highest in the sky. High noon is another way of saying it. Shakespeare used it in his Comedy of Errors, 1590:

There's none but witches do inhabit here;

And therefore 'tis high time that I were hence.