It’s 23 past 9 (Official clock system).

21:23

It’s 23 past 9.

Correct answer

21:24

It’s 24 past 9.

Error: 1 minute later

21:07

It’s 7 past 9.

Error: read minutes starting from hour markings and adding minutes

17:45

It’s a quarter to 6.

Error: confuse hour and minute hands