times in Java

[js06am]

Just working over some past-exam paper questions in preparation for my upcoming programing exam and I'm a little confused by the following:

"Imagine that you have written a class o produce a four-digit clock display (showing times as a 24-hour clock, for example "14:30"). List four example of (legal) times that would be useful for testing that the display works correctly."

Now this question is from a paper that is 2 years old so I apologise if it is out-dated, I'm just looking for clarification as marking-schemes for past-papers are not available.

Thanks for your time.

[JosAH]

I don't know whether or not I understand your question but I do like it; I would
pick the following four times:

09:46
18:23
23:54
07:15

All digits are unique per time, the digits 0, 1, 2, 3, 4 and 5 appear twice, the
digits 6, 7, 8 and 9 appear once and never, except for zero appear the digits
twice in the same position. It's a bit like a magic square ;-)

kind regards,

Jos