javascript regexp for numbers between 00-59 (seconds)

Question

I want to check if a field is a valid time value (just seconds). So I want to accept the numbers from 0 to 59. I came out with this:

[0-5][0-9]?

Answer 1

If you want to make the tens digit optional, not the unit position, place the ? there:

[0-5]?[0-9]