I want a regexp for matching time in HH:MM format. Here's what I have, and it works:
^[0-2][0-3]:[0-5][0-9]$
This matches everything from 00:00 to 23:59.
However, I want to change it so 0:00 and 1:00, etc are also matched as well as 00:00 and 01:30. I.e to make the leftmost digit optional, to match HH:MM as well as H:MM.
Any ideas how to make that change? I need this to work in javascript as well as php.
21 Answers
Your original regular expression has flaws: it wouldn't match 04:00 for example.
This may work better:
^([0-1]?[0-9]|2[0-3]):[0-5][0-9]$
Regular Expressions for Time
HH:MM 12-hour format, optional leading 0
/^(0?[1-9]|1[0-2]):[0-5][0-9]$/HH:MM 12-hour format, optional leading 0, mandatory meridiems (AM/PM)
/((1[0-2]|0?[1-9]):([0-5][0-9]) ?([AaPp][Mm]))/HH:MM 24-hour with leading 0
/^(0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]$/HH:MM 24-hour format, optional leading 0
/^([0-9]|0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]$/HH:MM:SS 24-hour format with leading 0
/(?:[01]\d|2[0-3]):(?:[0-5]\d):(?:[0-5]\d)/
None of the above worked for me. In the end I used:
^([0-1]?[0-9]|2[0-3]):[0-5][0-9]$ (js engine)
Logic:
The first number (hours) is either:
a number between 0 and 19 --> [0-1]?[0-9] (allowing single digit number)
or
a number between 20 - 23 --> 2[0-3]
the second number (minutes) is always a number between 00 and 59 --> [0-5][0-9] (not allowing a single digit)
You can use this one 24H, seconds are optional
^([0-1]?[0-9]|[2][0-3]):([0-5][0-9])(:[0-5][0-9])?$
The best would be for HH:MM without taking any risk.
^(0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]$
Amazingly I found actually all of these don't quite cover it, as they don't work for shorter format midnight of 0:0 and a few don't work for 00:00 either, I used and tested the following:
^([0-9]|0[0-9]|1?[0-9]|2[0-3]):[0-5]?[0-9]$
You can use this regular expression:
^(2[0-3]|[01]?[0-9]):([1-5]{1}[0-9])$
If you want to exclude 00:00, you can use this expression
^(2[0-3]|[01]?[0-9]):(0[1-9]{1}|[1-5]{1}[0-9])$
Second expression is better option because valid time is 00:01 to 00:59 or 0:01 to 23:59. You can use any of these upon your requirement. Regex101 link
As you asked the left most bit optional, I have done left most and right most bit optional too, check it out
^([0-9]|0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]?$
It matches with
0:0
00:00
00:0
0:00
23:59
01:00
00:59
The live link is available here
None of the above answers worked for me, the following one worked.
"[0-9]{2}:[0-9]{2}"
To validate 24h time, use:
^([0-1]?[0-9]|2?[0-3]|[0-9])[:\-\/]([0-5][0-9]|[0-9])$
This accepts:
22:10
2:10
2/1
...
But does not accept:
25:12
12:61
...
Description
hours:minutes with:
- Mandatory
am|pmorAM|PM - Mandatory leading zero
05:01instead of5:1 - Hours from
01up to12 - Hours does not accept
00as in00:16 am - Minutes from
00up to59
01:16 am ✅
01:16 AM ✅
01:16 ❌ (misses am|pm)
01:16 Am❌ (am must all be either lower or upper case)
1:16 am ❌ (Hours misses leading zero)
00:16 ❌ (Invalid hours value 00)
