Utility Function: IsTime()

My company often splits up date and time entries on forms, and then concatenates them back together on the back end. This is fine, except the time inputs are prone to errors, as IsDate() seems to be the only built in check to see if a string is a time, and it matches on things that are not purely times. To get around this, I create a new check: IsTime().

<cffunction name="IsTime" access="public" output="false" returntype="boolean">
    <cfargument name="time" type="string" required="true" />
    <cfreturn ArrayLen(REMatchNoCase("^((0?\d|1[012]):[0-5]\d ?(am|pm)|[0-2]?\d:[0-5]\d)$", arguments.time)) gt 0 />


String IsDate()? IsTime()?
3:45 am 1/1/2008 YES NO
12:65 am NO NO
47:00 NO NO
09:34 PM YES YES
1/1/2008 3:45 am YES NO
3:45am YES YES
3:45 am YES YES
09 13:45 YES NO
[Empty String] NO NO
14:05 YES YES
13:00 pm YES NO
1/1/2008 13:45 YES NO
4:45 YES YES
12:45 am YES YES



Jon Hartmann, July 2011

I'm Jon Hartmann and I'm a Javascript fanatic, UX/UI evangelist and former ColdFusion master. I blog about mysterious error messages, user interface design questions, and all things baffling and irksome about programming for the web.

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