RegEx Short Date Validation (14-Mar-98)

Here's a little JavaScript function to validate short date formatted values (14-Mar-98). Just pass in the form element and let the function to the rest. Checks for valid format as well as valid days, months, and years.

Here's a little JavaScript function to validate short date formatted values (14-Mar-98). Just pass in the form element and let the function to the rest. Checks for valid format as well as valid days, months, and years.


function ValidateShortDate(oField)
{
/*
validates an input field for dates formatted as dd-Mth-yy or (14-Mar-03)
*/

var sDate = oField.value.toUpperCase();
var bValid = false;
var aMatch =/^\d{2}[\/-](JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)[\/-]\d{2}$/.exec(sDate);

if (sDate.length==0) { return true; }

if (aMatch == null)
{
alert(sDate + " is not in 14-Mar-03 format."); oField.focus();
oField.value='';
return bValid;
}

var DateArray = sDate.split("-");

// Convert the text month to a number - zero based month

switch (DateArray[1])
{
case "JAN": DateArray[1] = 0; break;
case "FEB": DateArray[1] = 1; break;
case "MAR": DateArray[1] = 2; break;
case "APR": DateArray[1] = 3; break;
case "MAY": DateArray[1] = 4; break;
case "JUN": DateArray[1] = 5; break;
case "JUL": DateArray[1] = 6; break;
case "AUG": DateArray[1] = 7; break;
case "SEP": DateArray[1] = 8; break;
case "OCT": DateArray[1] = 9; break;
case "NOV": DateArray[1] = 10; break;
case "DEC": DateArray[1] = 11; break;
}

// Use 1970 as the breaking point for determining whether the year
// should be >= 2000 or 1900.

if (DateArray[2] < 70) { DateArray[2] = 20 + DateArray[2]; }
else { DateArray[2] = 19 + DateArray[2]; }

var oDate = new Date();

oDate.setFullYear(DateArray[2]);
oDate.setMonth(DateArray[1]);
oDate.setDate(DateArray[0]);

// Validate whether the date itself is a valid calendar date.

if ((DateArray[2] != oDate.getFullYear()) || (DateArray[1] != oDate.getMonth()))
{
oField.value='';
alert(sDate + " has the right format, \n" + "but is not a valid calendar date.");
return bValid;
}


bValid = true;
return bValid;
}


Submission Date:  9/23/2005 2:55:34 PM
Submitted By:  Robbe Morris
My Home Page:  http://www.robbemorris.com