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

Question

/^\\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 unifo

Answer 1

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.