Regex and ISO8601 formatted DateTime

Don't quote the regex when specifying a regex in js. Forward slash is enough.

alert($('#datepicker').val());

if($('#datepicker').val().match(
    /(\d{4})-(\d{2})-(\d{2})T(\d{2})\:(\d{2})\:(\d{2})[+-](\d{2})\:(\d{2})/
)) {
    alert('ok');
} else {
    alert('not ok');
}​

Incomplete Regex

It's incomplete as it matches invalid date such as 2013-99-99T04:13:00+00:00.

Better solution

The regex below won't match this kind of invalid date (cf. ISO 8601 Date Validation That Doesn’t Suck). You can test with the following code :

re = /^([\+-]?\d{4}(?!\d{2}\b))((-?)((0[1-9]|1[0-2])(\3([12]\d|0[1-9]|3[01]))?|W([0-4]\d|5[0-2])(-?[1-7])?|(00[1-9]|0[1-9]\d|[12]\d{2}|3([0-5]\d|6[1-6])))([T\s]((([01]\d|2[0-3])((:?)[0-5]\d)?|24\:?00)([\.,]\d+(?!:))?)?(\17[0-5]\d([\.,]\d+)?)?([zZ]|([\+-])([01]\d|2[0-3]):?([0-5]\d)?)?)?)?$/
var testDates = {
    'date' : "2012-10-06T04:13:00+00:00",
    'validDate' : "0785-10-10T04:13:00+00:00",
    'invalidDate' : "2013-99-99T04:13:00+00:00",
    '1234Date': '1234'
}
for (var d in testDates) {
    if (re.test(testDates[d])) { console.info('[valid]: '+testDates[d]); }
    else { console.error('[invalid]: '+testDates[d]); }
}

I found the RegExp that also tries to validate the date a bit overkill for me. I Just wanted to know if a string contains an ISO 8601 date string. I'll check if the date is actually valid after I have converted it to a Date object.

Here are 2 versions of the RegExp. This first checks if the string is a valid ISO 8601 date string. The other tests for a full date string including the hours/minutes/seconds (Commonly used in API's)

/**
 * RegExp to test a string for a ISO 8601 Date spec
 *  YYYY
 *  YYYY-MM
 *  YYYY-MM-DD
 *  YYYY-MM-DDThh:mmTZD
 *  YYYY-MM-DDThh:mm:ssTZD
 *  YYYY-MM-DDThh:mm:ss.sTZD
 * @see: https://www.w3.org/TR/NOTE-datetime
 * @type {RegExp}
 */
var ISO_8601 = /^\d{4}(-\d\d(-\d\d(T\d\d:\d\d(:\d\d)?(\.\d+)?(([+-]\d\d:\d\d)|Z)?)?)?)?$/i



/**
 * RegExp to test a string for a full ISO 8601 Date
 * Does not do any sort of date validation, only checks if the string is according to the ISO 8601 spec.
 *  YYYY-MM-DDThh:mm:ss
 *  YYYY-MM-DDThh:mm:ssTZD
 *  YYYY-MM-DDThh:mm:ss.sTZD
 * @see: https://www.w3.org/TR/NOTE-datetime
 * @type {RegExp}
 */
var ISO_8601_FULL = /^\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d(\.\d+)?(([+-]\d\d:\d\d)|Z)?$/i


// Usage:

ISO_8601_FULL.test( "2016-05-24T15:54:14.876Z" )  // true
ISO_8601_FULL.test( "2002-12-31T23:00:00+01:00" ) // true
ISO_8601_FULL.test( "2016-02-01" )                // false
ISO_8601_FULL.test( "2016" )                      // false

ISO_8601.test( "2016-02-01" )                     // true
ISO_8601.test( "2016" )                           // true
ISO_8601.test( "2002-12-31T23:00:00+01:00" )      // true