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JavaScript Date Validation

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4.93/5 (17 votes)
29 Nov 2012CPOL1 min read 223.6K   22   30
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:
 
C#
//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 : 0var 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).

(From http://www.ventanazul.com/webzine/articles/issues-parseint-javascript[^])
 
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.

License

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


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Comments and Discussions

 
BugDefault day, month, year indexes will not work. Also, param sepVal is not working properly. Pin
Min Htun Zaw5-Oct-13 0:51
Min Htun Zaw5-Oct-13 0:51 
SuggestionNewer version Pin
Master DJon5-Dec-12 6:24
Master DJon5-Dec-12 6:24 
GeneralRe: Newer version Pin
joni8a5-Mar-13 3:30
joni8a5-Mar-13 3:30 
AnswerRe: Newer version Pin
Master DJon5-Mar-13 7:10
Master DJon5-Mar-13 7:10 
AnswerRe: Newer version Pin
Master DJon5-Mar-13 8:55
Master DJon5-Mar-13 8:55 
QuestionShorter code Pin
redphx4-Dec-12 20:13
redphx4-Dec-12 20:13 
QuestionAlternative to parseInt() Pin
Daniel Trott4-Dec-12 6:03
Daniel Trott4-Dec-12 6:03 
QuestionImpressive, but have a couple of mods that should take care of both the date format and the separator for diff countries. Pin
Lester Callif27-Nov-12 15:46
Lester Callif27-Nov-12 15:46 
AnswerRe: Impressive, but have a couple of mods that should take care of both the date format and the separator for diff countries. Pin
Ed Nutting29-Nov-12 10:52
Ed Nutting29-Nov-12 10:52 
GeneralRe: Impressive, but have a couple of mods that should take care of both the date format and the separator for diff countries. Pin
Lester Callif29-Nov-12 12:50
Lester Callif29-Nov-12 12:50 
AnswerRe: Impressive, but have a couple of mods that should take care of both the date format and the separator for diff countries. Pin
Ed Nutting30-Nov-12 9:16
Ed Nutting30-Nov-12 9:16 
AnswerRe: Impressive, but have a couple of mods that should take care of both the date format and the separator for diff countries. Pin
Ed Nutting29-Nov-12 11:01
Ed Nutting29-Nov-12 11:01 
QuestionJust one bug in February Pin
Member 324090521-Nov-12 12:37
Member 324090521-Nov-12 12:37 
AnswerRe: Just one bug in February Pin
Ed Nutting25-Nov-12 11:09
Ed Nutting25-Nov-12 11:09 
QuestionDesign flaw in your code Pin
Member 942879613-Sep-12 13:38
Member 942879613-Sep-12 13:38 
AnswerRe: Design flaw in your code Pin
Ed Nutting13-Sep-12 20:26
Ed Nutting13-Sep-12 20:26 
BugYear Validation Pin
XtremLucky24-Apr-12 3:05
XtremLucky24-Apr-12 3:05 
GeneralRe: Year Validation Pin
Ed Nutting24-Apr-12 6:16
Ed Nutting24-Apr-12 6:16 
GeneralRe: Year Validation Pin
greg_ryan17-Jul-12 12:54
greg_ryan17-Jul-12 12:54 
GeneralMinor Bug Fix for the non-slash people... Pin
Ed Nutting13-Mar-12 12:11
Ed Nutting13-Mar-12 12:11 
GeneralI am *very* surprised that none of our North American friend... Pin
Peter_in_278026-Sep-11 16:15
professionalPeter_in_278026-Sep-11 16:15 
GeneralRe: Yes I guess that is a little surprising. But then again, I w... Pin
Ed Nutting26-Sep-11 20:19
Ed Nutting26-Sep-11 20:19 
GeneralReason for my vote of 5 found to be complete, simple and ele... Pin
rquadros25-Jul-11 12:34
rquadros25-Jul-11 12:34 
QuestionBug with year validation Pin
Member 842090121-Nov-11 5:59
Member 842090121-Nov-11 5:59 
AnswerRe: Bug with year validation Pin
Ed Nutting21-Nov-11 9:42
Ed Nutting21-Nov-11 9:42 

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