I am newbie in Regular Expressions. 

I need to check this time 18:00(00:00, 01:00, 05:12, any time of this format) by regexp, is it correct or no.

Here is my variant:

```
/[0-9][0-9]:[0-9][0-9]/

```

Can I change [0-9][0-9] to something like 2\*[0-9] ???