Question

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] ???

Answer 1

If you specifically want to match 18:00 you should use /^\d{2}:\d{2}$/. The answers provided so far will match aaa12:99ddd. The ^ and $ are anchors and will instruct the regex to match specifically the given string.

If you are after a 24 hour validation regular expression you could use this: /^([01]?[0-9]|2[0-3]):[0-5][0-9]$/ (taken from here).