Click here to Skip to main content
11,923,948 members (64,866 online)
Click here to Skip to main content
Add your own
alternative version

Tagged as


21 bookmarked

JavaScript Date Validation

, 29 Nov 2012 CPOL
Rate this:
Please Sign up or sign in to vote.
JavaScript Date Validation
For a few days now, I have been battling with the problem of JavaScript date validation. I wanted to validate text inputed by a user as they were typing to tell them if it was a valid date. After much searching on the internet, I found nothing that worked. So I wrote the following code to do the job, it is a simple but effective isDate function:
//Value parameter - required. All other parameters are optional.
function isDate(value, sepVal, dayIdx, monthIdx, yearIdx) {
    try {
        //Change the below values to determine which format of date you wish to check. It is set to dd/mm/yyyy by default.
        var DayIndex = dayIdx !== undefined ? dayIdx : 0; 
        var MonthIndex = monthIdx !== undefined ? monthIdx : 0;
        var YearIndex = yearIdx !== undefined ? yearIdx : 0;
        value = value.replace(/-/g, "/").replace(/\./g, "/"); 
        var SplitValue = value.split(sepVal || "/");
        var OK = true;
        if (!(SplitValue[DayIndex].length == 1 || SplitValue[DayIndex].length == 2)) {
            OK = false;
        if (OK && !(SplitValue[MonthIndex].length == 1 || SplitValue[MonthIndex].length == 2)) {
            OK = false;
        if (OK && SplitValue[YearIndex].length != 4) {
            OK = false;
        if (OK) {
            var Day = parseInt(SplitValue[DayIndex], 10);
            var Month = parseInt(SplitValue[MonthIndex], 10);
            var Year = parseInt(SplitValue[YearIndex], 10);
            if (OK = ((Year > 1900) && (Year < new Date().getFullYear()))) {
                if (OK = (Month <= 12 && Month > 0)) {

                    var LeapYear = (((Year % 4) == 0) && ((Year % 100) != 0) || ((Year % 400) == 0));   
                    if(OK = Day > 0)
                        if (Month == 2) {  
                            OK = LeapYear ? Day <= 29 : Day <= 28;
                        else {
                            if ((Month == 4) || (Month == 6) || (Month == 9) || (Month == 11)) {
                                OK = Day <= 30;
                            else {
                                OK = Day <= 31;
        return OK;
    catch (e) {
        return false;
Just copy the above function and call isDate(value) where value is a string containing a valid or invalid date. The function returns a bool true if the string was a date and false if it wasn't. Hope this helps! Smile | <img src= " />
EDIT: Thanks to Member 2792937 for bringing a bug to my attention.
Both parseInt('08') and parseInt('09') return zero because the function tries to determine the correct base for the numerical system used. In JavaScript, numbers starting with zero are considered octal and there's no 08 or 09 in octal, hence the problem.
To fix this, just add the second parameter for parseInt, the base to be used for the conversion. The correct calls should be parseInt('08', 10) and parseInt('09', 10).

I have modified my code to fix this issue.

EDIT: Now includes optional parameters for specifying separator value and the indexes. To miss out a parameter simply pass in undefined. Thanks to Lester Callif for the suggestions.


This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


About the Author

Ed Nutting
United Kingdom United Kingdom

I am Edward Nutting, born March 1996 and I am currently a Computer Science and Electronic Engineering undergraduate at the University of Bristol, UK. I've been self-teaching programming since I was eight years old and have dabbled in many different areas from web development (where I had my own advertising startup) to low level operating system stuff (my current project Fling OS).

The articles and code on this profile are some of my early work (from when I was aged about 13 to 16) but despite my young age, it has been well received by CodeProject users. My more recent work has been for companies or on projects hosted on GitHub, CodePlex or BitBucket.

I keep an eye on many things techy and am open to any and all ideas, so please feel free to contact me if you think I can help! Smile | :)

Ed Nutting

You may also be interested in...

Comments and Discussions

GeneralI am *very* surprised that none of our North American friend... Pin
Peter_in_278026-Sep-11 17:15
memberPeter_in_278026-Sep-11 17:15 
GeneralRe: Yes I guess that is a little surprising. But then again, I w... Pin
Edward Nutting26-Sep-11 21:19
memberEdward Nutting26-Sep-11 21:19 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.

| Advertise | Privacy | Terms of Use | Mobile
Web01 | 2.8.151125.3 | Last Updated 29 Nov 2012
Article Copyright 2011 by Ed Nutting
Everything else Copyright © CodeProject, 1999-2015
Layout: fixed | fluid