CODEWITHSUNDEEP
phpregexdatetimetime
Adrian Sarli
Adrian Sarli

Reputation: 2356

How do you match 12 hour time hh:mm in a regex?

How could you match 12 hour time in a regex-- in other words match 12:30 but not 14:74? Thanks!

Upvotes: 5

Views: 12111

Answers (11)

Kurt
Kurt

Reputation: 1

Here is a 12 hour pattern with AM and PM validation.

TIME12HOURSAMPM_PATTERN = "^(?:(?<!\\d)[0-9]|0[0-9]|1[0-2]):[0-5][0-9] ?((a|p)m|(A|P)M)$";

Upvotes: 0

Eli
Eli

Reputation: 99368

^(00|0[0-9]|1[012]):[0-5][0-9] ?((a|p)m|(A|P)M)$

^ - Match the beginning of the string.

(00|0[0-9]|1[012]) - any two-digit number up to 12. Require two digits.

: - Match a colon

[0-5][0-9] - Match any two-digit number from 00 to 59.

? - Match a space zero or one times.

((a|p)m|(A|P)M) - Match am or pm, case insensitive.

$ - Match the end of the string.

Upvotes: 8

SquareRootOf2
SquareRootOf2

Reputation: 393

^(?:(?:1?(?:[0-2]))|[1-9]):[0-5][0-9]

Upvotes: 0

Keith
Keith

Reputation: 5381

This should work:

([1-9]|1[012]):[0-5][0-9]

Upvotes: 17

ghostdog74
ghostdog74

Reputation: 342333

why regex? you can do this will simple integer check

$str = "12:74";
list($h , $m ) = explode(":",$str);
if ( ($h <=12 && $h >=0  ) && ($m <=59 && $m >=0) ) {
    print "Time Ok.";
}else{
    print "Time not ok";
}

Upvotes: 1

MyItchyChin
MyItchyChin

Reputation: 14041

The following matches padded and non-padded hours in a 24hr clock (i.e. 00:00 - 23:59) between 00:00 and 12:59.

(?:(?<!\d)[0-9]|0[0-9]|1[0-2]):[0-5][0-9]

Matches:

  • 00:00
  • 00:58
  • 01:34
  • 1:34
  • 8:35
  • 12:23
  • 12:59

Nonmatches:

  • 13:00
  • 13:23
  • 14:45
  • 23:59

Upvotes: 0

PatrikAkerstrand
PatrikAkerstrand

Reputation: 45721

You could use this one:

/((?:1[0-2])|(?:0?[0-9])):([0-5][0-9]) ?([ap]m)/

/1 => hour
/2 => minute
/3 => am/pm

Upvotes: 0

Daniel C. Sobral
Daniel C. Sobral

Reputation: 297165

(0?\d|1[0-2]):([0-5]\d)

That will match everything from 0:00 up to 12:59. That's 13 hours, by the way. If you don't want to match 0:00 - 0:59, try this instead:

([1-9]|1[0-2]):([0-5]\d)

Upvotes: 0

Andr&#233; Eriksson
Andr&#233; Eriksson

Reputation: 4360

I believe the above fail in at least one way, particularly regarding strings such as "13:00" (Keith's matches "3:00" in that case).

This one should handle that issue as well as the others brought up.

([01][0-2]|(?<!1)[0-9]):([0-5][0-9])

Upvotes: 0

Greg Hewgill
Greg Hewgill

Reputation: 992937

This is an example of a problem where "hey I know, I'll use regular expressions!" is the wrong solution. You can use a regular expression to check that your input format is digit-digit-colon-digit-digit, then use programming logic to ensure that the values are within the range you expect. For example:

/(\d\d?):(\d\d)/

if ($1 >= 1 && $1 <= 12 && $2 < 60) {
    // result is valid 12-hour time
}

This is much easier to read and understand than some of the obfuscated regex examples you see in other answers here.

Upvotes: 16

instanceof me
instanceof me

Reputation: 39138

Like this: ((?:1[0-2]|0\d)\:(?:[0-5]\d)) if you want leading 0 for the hour, ((?:1[0-2]|\d)\:(?:[0-5]\d)) if you don't and ((?:1[0-2]|0?\d)\:(?:[0-5]\d)) if you don't care.

Upvotes: 1

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