CODEWITHSUNDEEP
javascriptregex
Joshua Enfield
Joshua Enfield

Reputation: 18288

RegEx - Time Validation ((h)h:mm)

/^\d{1,2}[:][0-5][0-9]$/

is what I have. this limits minutes to 00-59. It does not, however, limit hours to between 0 and 12. For similarity and uniformity I would like to do this with RegEx alone if possible.

Further-more I would like the first digit to be optional. i.e. 09:30 accepted as well as 9:30. I played around with ranges, but something out of range is always acceptable.

Upvotes: 15

Views: 45957

Answers (7)

codrut51
codrut51

Reputation: 1

^(([0-9]{1})|([0-1]{1}[0-9]{1})|([2]{1}[0-3]{1}))(([:]{1})?)(([0-5]{1}[0-9]?)?)$

  • 29:30 <- invalid
  • 9:21 <- valid
  • 13:25 <- valid
  • 19:01 <- valid
  • 19:62 <- invalid
  • 24:00 <- invalid
  • 23:59 <- valid
  • 00:00 <- valid
  • 1 <- valid (can be sanitized to 01:00)
  • 20 <- valid (can be sanitized to 20:00)
  • 20: <- valid (can be sanitized to 20:00)
  • 20:5 <- valid (can be sanitized to 20:50)

^(([0-9]{1})|([0-1]{1}[0-9]{1})|([2]{1}[0-3]{1}))([:]{1})([0-5]{1}[0-9]{1})$

  • 29:30 <- invalid
  • 9:21 <- valid
  • 13:25 <- valid
  • 19:01 <- valid
  • 19:62 <- invalid
  • 24:00 <- invalid
  • 23:59 <- valid
  • 00:00 <- valid
  • 1 <- invalid
  • 20 <- invalid
  • 20: <- invalid
  • 20:5 <- invalid

Upvotes: 0

Nikhil VJ
Nikhil VJ

Reputation: 6112

For folks looking for 24h format matching,

hh:mm:ss or h:mm:ss : 

status = /^(2[0-3]|[0-1]?[\d]):[0-5][\d]:[0-5][\d]$/.test(timestr)

hh:mm or h:mm :

status = /^(2[0-3]|[0-1]?[\d]):[0-5][\d]$/.test(timestr)

This site is great for testing out: https://www.regexpal.com/

Addedum: Explanation for completeness:

  • ^ : start of string, $ : end of string. So we put the expression in a ^..$ block to ensure there's nothing outside of our pattern.
  • (2[0-3]|[0-1]?[\d]) : translates to 2[0-3] OR [0-1]?[\d]
  • 2[0-3] : 20, 21, 22, 23
  • [0-1]?[\d] : 0 or 1 or nothing (?) followed by any single digit(\d). So, this works for numbers from 0 to 19.
  • : just that character
  • [0-5][\d] : number from 00 to 59. Note: this won't tolerate single-digit in the mm place.

Upvotes: 10

Byorn
Byorn

Reputation: 721

This is perfect: ^0?([0-9][0-2]?):[0-5][0-9]$

Note: 12 Hr Clock Only

For Times like: 0:01- 12:59

or

00:01 - 12:59

Upvotes: 0

Andrey
Andrey

Reputation: 21

Thanks!!! I use this Javascript code now:

function Check_arrival(time) { //Assuming you are working in 12 hour time, 0 is not a valid var patt = new RegExp("^(0?[1-9]|1[012]):[0-5][0-9]$"); var res = patt.test(time); return res; }

res=true|false

Upvotes: 2

Trey Hunner
Trey Hunner

Reputation: 11814

Assuming you are working in 12 hour time, 0 is not a valid hour and should also be excluded (as pointed out by Jon). Here is a basic solution:

/^(0?[1-9]|1[012]):[0-5][0-9]$/

A 24-hour time regex matcher that works similarly:

/^([01]?[0-9]|2[0-3]):[0-5][0-9]$/

Upvotes: 22

Jon Snyder
Jon Snyder

Reputation: 2009

/^(10|11|12|[1-9]):[0-5][0-9]$/

I don't think that you want 0:50 as a valid time either.

Upvotes: 7

kennytm
kennytm

Reputation: 523304

The 0 - 9 and 10 - 12 cases need to be treated separately. (The two rules can be combined with |.)

/^(?:0?\d|1[012]):[0-5]\d$/

Here

  • (?:…) is a non-capturing group
  • x|y means match either pattern
  • 0?\d matches 0 - 9 or 00 - 09
  • 1[012] matches 10 - 12.

Upvotes: 12

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