validation – How to validate date with format "mm/dd/yyyy" in JavaScript?-ThrowExceptions

Exception or error:

I want to validate the date format on an input using the format mm/dd/yyyy.

I found below codes in one site and then used it but it doesn’t work:

function isDate(ExpiryDate) { 
    var objDate,  // date object initialized from the ExpiryDate string 
        mSeconds, // ExpiryDate in milliseconds 
        day,      // day 
        month,    // month 
        year;     // year 
    // date length should be 10 characters (no more no less) 
    if (ExpiryDate.length !== 10) { 
        return false; 
    } 
    // third and sixth character should be '/' 
    if (ExpiryDate.substring(2, 3) !== '/' || ExpiryDate.substring(5, 6) !== '/') { 
        return false; 
    } 
    // extract month, day and year from the ExpiryDate (expected format is mm/dd/yyyy) 
    // subtraction will cast variables to integer implicitly (needed 
    // for !== comparing) 
    month = ExpiryDate.substring(0, 2) - 1; // because months in JS start from 0 
    day = ExpiryDate.substring(3, 5) - 0; 
    year = ExpiryDate.substring(6, 10) - 0; 
    // test year range 
    if (year < 1000 || year > 3000) { 
        return false; 
    } 
    // convert ExpiryDate to milliseconds 
    mSeconds = (new Date(year, month, day)).getTime(); 
    // initialize Date() object from calculated milliseconds 
    objDate = new Date(); 
    objDate.setTime(mSeconds); 
    // compare input date and parts from Date() object 
    // if difference exists then date isn't valid 
    if (objDate.getFullYear() !== year || 
        objDate.getMonth() !== month || 
        objDate.getDate() !== day) { 
        return false; 
    } 
    // otherwise return true 
    return true; 
}

function checkDate(){ 
    // define date string to test 
    var ExpiryDate = document.getElementById(' ExpiryDate').value; 
    // check date and print message 
    if (isDate(ExpiryDate)) { 
        alert('OK'); 
    } 
    else { 
        alert('Invalid date format!'); 
    } 
}

Any suggestion about what could be wrong?

How to solve:

I think Niklas has the right answer to your problem. Besides that, I think the following date validation function is a little bit easier to read:

// Validates that the input string is a valid date formatted as "mm/dd/yyyy"
function isValidDate(dateString)
{
    // First check for the pattern
    if(!/^\d{1,2}\/\d{1,2}\/\d{4}$/.test(dateString))
        return false;

    // Parse the date parts to integers
    var parts = dateString.split("/");
    var day = parseInt(parts[1], 10);
    var month = parseInt(parts[0], 10);
    var year = parseInt(parts[2], 10);

    // Check the ranges of month and year
    if(year < 1000 || year > 3000 || month == 0 || month > 12)
        return false;

    var monthLength = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];

    // Adjust for leap years
    if(year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
        monthLength[1] = 29;

    // Check the range of the day
    return day > 0 && day <= monthLength[month - 1];
};

###

I would use Moment.js for date validation.

alert(moment("05/22/2012", 'MM/DD/YYYY',true).isValid()); //true

Jsfiddle: http://jsfiddle.net/q8y9nbu5/

true value is for strict parsing credit to @Andrey Prokhorov which means

you may specify a boolean for the last argument to make Moment use
strict parsing. Strict parsing requires that the format and input
match exactly, including delimeters.

###

Use the following regular expression to validate:

var date_regex = /^(0[1-9]|1[0-2])\/(0[1-9]|1\d|2\d|3[01])\/(19|20)\d{2}$/;
if (!(date_regex.test(testDate))) {
    return false;
}

This is working for me for MM/dd/yyyy.

###

All credits go to elian-ebbing

Just for the lazy ones here I also provide a customized version of the function for the format yyyy-mm-dd.

function isValidDate(dateString)
{
    // First check for the pattern
    var regex_date = /^\d{4}\-\d{1,2}\-\d{1,2}$/;

    if(!regex_date.test(dateString))
    {
        return false;
    }

    // Parse the date parts to integers
    var parts   = dateString.split("-");
    var day     = parseInt(parts[2], 10);
    var month   = parseInt(parts[1], 10);
    var year    = parseInt(parts[0], 10);

    // Check the ranges of month and year
    if(year < 1000 || year > 3000 || month == 0 || month > 12)
    {
        return false;
    }

    var monthLength = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];

    // Adjust for leap years
    if(year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
    {
        monthLength[1] = 29;
    }

    // Check the range of the day
    return day > 0 && day <= monthLength[month - 1];
}

###

You could use Date.parse()

You can read in MDN documentation

The Date.parse() method parses a string representation of a date, and
returns the number of milliseconds since January 1, 1970, 00:00:00 UTC
or NaN if the string is unrecognized or, in some cases, contains
illegal date values (e.g. 2015-02-31).

And check if the result of Date.parse isNaN

let isValidDate = Date.parse('01/29/1980');

if (isNaN(isValidDate)) {
  // when is not valid date logic

  return false;
}

// when is valid date logic

Please take a look when is recommended to use Date.parse in MDN

###

It appears to be working fine for mm/dd/yyyy format dates, example:

http://jsfiddle.net/niklasvh/xfrLm/

The only problem I had with your code was the fact that:

var ExpiryDate = document.getElementById(' ExpiryDate').value;

Had a space inside the brackets, before the element ID. Changed it to:

var ExpiryDate = document.getElementById('ExpiryDate').value;

Without any further details regarding the type of data that isn’t working, there isn’t much else to give input on.

###

The function will return true if the given string is in the right format(‘MM/DD/YYYY’) else it will return false. (I found this code online & modified it a little)

function isValidDate(date) {
    var temp = date.split('/');
    var d = new Date(temp[2] + '/' + temp[0] + '/' + temp[1]);
    return (d && (d.getMonth() + 1) == temp[0] && d.getDate() == Number(temp[1]) && d.getFullYear() == Number(temp[2]));
}

console.log(isValidDate('02/28/2015'));
            

###

Here is one snippet to check for valid date:

function validateDate(dateStr) {
   const regExp = /^(\d\d?)\/(\d\d?)\/(\d{4})$/;
   let matches = dateStr.match(regExp);
   let isValid = matches;
   let maxDate = [0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
   
   if (matches) {
     const month = parseInt(matches[1]);
     const date = parseInt(matches[2]);
     const year = parseInt(matches[3]);
     
     isValid = month <= 12 && month > 0;
     isValid &= date <= maxDate[month] && date > 0;
     
     const leapYear = (year % 400 == 0)
        || (year % 4 == 0 && year % 100 != 0);
     isValid &= month != 2 || leapYear || date <= 28; 
   }
   
   return isValid
}

console.log(['1/1/2017', '01/1/2017', '1/01/2017', '01/01/2017', '13/12/2017', '13/13/2017', '12/35/2017'].map(validateDate));

###

It’s ok if you want to check validate dd/MM/yyyy

function isValidDate(date) {
    var temp = date.split('/');
    var d = new Date(temp[1] + '/' + temp[0] + '/' + temp[2]);
     return (d && (d.getMonth() + 1) == temp[1] && d.getDate() == Number(temp[0]) && d.getFullYear() == Number(temp[2]));
}

alert(isValidDate('29/02/2015')); // it not exist ---> false
            

###

Find in the below code which enables to perform the date validation for any of the supplied format to validate start/from and end/to dates. There could be some better approaches but have come up with this. Note supplied date format and date string go hand in hand.

<script type="text/javascript">
    function validate() {

        var format = 'yyyy-MM-dd';

        if(isAfterCurrentDate(document.getElementById('start').value, format)) {
            alert('Date is after the current date.');
        } else {
            alert('Date is not after the current date.');
        }
        if(isBeforeCurrentDate(document.getElementById('start').value, format)) {
            alert('Date is before current date.');
        } else {
            alert('Date is not before current date.');
        }
        if(isCurrentDate(document.getElementById('start').value, format)) {
            alert('Date is current date.');
        } else {
            alert('Date is not a current date.');
        }
        if (isBefore(document.getElementById('start').value, document.getElementById('end').value, format)) {
            alert('Start/Effective Date cannot be greater than End/Expiration Date');
        } else {
            alert('Valid dates...');
        }
        if (isAfter(document.getElementById('start').value, document.getElementById('end').value, format)) {
            alert('End/Expiration Date cannot be less than Start/Effective Date');
        } else {
            alert('Valid dates...');
        }
        if (isEquals(document.getElementById('start').value, document.getElementById('end').value, format)) {
            alert('Dates are equals...');
        } else {
            alert('Dates are not equals...');
        }
        if (isDate(document.getElementById('start').value, format)) {
            alert('Is valid date...');
        } else {
            alert('Is invalid date...');
        }
    }

    /**
     * This method gets the year index from the supplied format
     */
    function getYearIndex(format) {

        var tokens = splitDateFormat(format);

        if (tokens[0] === 'YYYY'
                || tokens[0] === 'yyyy') {
            return 0;
        } else if (tokens[1]=== 'YYYY'
                || tokens[1] === 'yyyy') {
            return 1;
        } else if (tokens[2] === 'YYYY'
                || tokens[2] === 'yyyy') {
            return 2;
        }
        // Returning the default value as -1
        return -1;
    }

    /**
     * This method returns the year string located at the supplied index
     */
    function getYear(date, index) {

        var tokens = splitDateFormat(date);
        return tokens[index];
    }

    /**
     * This method gets the month index from the supplied format
     */
    function getMonthIndex(format) {

        var tokens = splitDateFormat(format);

        if (tokens[0] === 'MM'
                || tokens[0] === 'mm') {
            return 0;
        } else if (tokens[1] === 'MM'
                || tokens[1] === 'mm') {
            return 1;
        } else if (tokens[2] === 'MM'
                || tokens[2] === 'mm') {
            return 2;
        }
        // Returning the default value as -1
        return -1;
    }

    /**
     * This method returns the month string located at the supplied index
     */
    function getMonth(date, index) {

        var tokens = splitDateFormat(date);
        return tokens[index];
    }

    /**
     * This method gets the date index from the supplied format
     */
    function getDateIndex(format) {

        var tokens = splitDateFormat(format);

        if (tokens[0] === 'DD'
                || tokens[0] === 'dd') {
            return 0;
        } else if (tokens[1] === 'DD'
                || tokens[1] === 'dd') {
            return 1;
        } else if (tokens[2] === 'DD'
                || tokens[2] === 'dd') {
            return 2;
        }
        // Returning the default value as -1
        return -1;
    }

    /**
     * This method returns the date string located at the supplied index
     */
    function getDate(date, index) {

        var tokens = splitDateFormat(date);
        return tokens[index];
    }

    /**
     * This method returns true if date1 is before date2 else return false
     */
    function isBefore(date1, date2, format) {
        // Validating if date1 date is greater than the date2 date
        if (new Date(getYear(date1, getYearIndex(format)), 
                getMonth(date1, getMonthIndex(format)) - 1, 
                getDate(date1, getDateIndex(format))).getTime()
            > new Date(getYear(date2, getYearIndex(format)), 
                getMonth(date2, getMonthIndex(format)) - 1, 
                getDate(date2, getDateIndex(format))).getTime()) {
            return true;
        } 
        return false;                
    }

    /**
     * This method returns true if date1 is after date2 else return false
     */
    function isAfter(date1, date2, format) {
        // Validating if date2 date is less than the date1 date
        if (new Date(getYear(date2, getYearIndex(format)), 
                getMonth(date2, getMonthIndex(format)) - 1, 
                getDate(date2, getDateIndex(format))).getTime()
            < new Date(getYear(date1, getYearIndex(format)), 
                getMonth(date1, getMonthIndex(format)) - 1, 
                getDate(date1, getDateIndex(format))).getTime()
            ) {
            return true;
        } 
        return false;                
    }

    /**
     * This method returns true if date1 is equals to date2 else return false
     */
    function isEquals(date1, date2, format) {
        // Validating if date1 date is equals to the date2 date
        if (new Date(getYear(date1, getYearIndex(format)), 
                getMonth(date1, getMonthIndex(format)) - 1, 
                getDate(date1, getDateIndex(format))).getTime()
            === new Date(getYear(date2, getYearIndex(format)), 
                getMonth(date2, getMonthIndex(format)) - 1, 
                getDate(date2, getDateIndex(format))).getTime()) {
            return true;
        } 
        return false;
    }

    /**
     * This method validates and returns true if the supplied date is 
     * equals to the current date.
     */
    function isCurrentDate(date, format) {
        // Validating if the supplied date is the current date
        if (new Date(getYear(date, getYearIndex(format)), 
                getMonth(date, getMonthIndex(format)) - 1, 
                getDate(date, getDateIndex(format))).getTime()
            === new Date(new Date().getFullYear(), 
                    new Date().getMonth(), 
                    new Date().getDate()).getTime()) {
            return true;
        } 
        return false;                
    }

    /**
     * This method validates and returns true if the supplied date value 
     * is before the current date.
     */
    function isBeforeCurrentDate(date, format) {
        // Validating if the supplied date is before the current date
        if (new Date(getYear(date, getYearIndex(format)), 
                getMonth(date, getMonthIndex(format)) - 1, 
                getDate(date, getDateIndex(format))).getTime()
            < new Date(new Date().getFullYear(), 
                    new Date().getMonth(), 
                    new Date().getDate()).getTime()) {
            return true;
        } 
        return false;                
    }

    /**
     * This method validates and returns true if the supplied date value 
     * is after the current date.
     */
    function isAfterCurrentDate(date, format) {
        // Validating if the supplied date is before the current date
        if (new Date(getYear(date, getYearIndex(format)), 
                getMonth(date, getMonthIndex(format)) - 1, 
                getDate(date, getDateIndex(format))).getTime()
            > new Date(new Date().getFullYear(),
                    new Date().getMonth(), 
                    new Date().getDate()).getTime()) {
            return true;
        } 
        return false;                
    }

    /**
     * This method splits the supplied date OR format based 
     * on non alpha numeric characters in the supplied string.
     */
    function splitDateFormat(dateFormat) {
        // Spliting the supplied string based on non characters
        return dateFormat.split(/\W/);
    }

    /*
     * This method validates if the supplied value is a valid date.
     */
    function isDate(date, format) {                
        // Validating if the supplied date string is valid and not a NaN (Not a Number)
        if (!isNaN(new Date(getYear(date, getYearIndex(format)), 
                getMonth(date, getMonthIndex(format)) - 1, 
                getDate(date, getDateIndex(format))))) {                    
            return true;
        } 
        return false;                                      
    }
</script>

Below is the HTML snippet

<input type="text" name="start" id="start" size="10" value="" />
<br/>
<input type="text" name="end" id="end" size="10" value="" />
<br/>
<input type="button" value="Submit" onclick="javascript:validate();" />

###

I pulled most of this code from another post found here. I have modified it for my purposes. This works well for what I need. It may help with your situation.

$(window).load(function() {
  function checkDate() {
    var dateFormat = /^(0?[1-9]|[12][0-9]|3[01])[\/\-](0?[1-9]|1[012])[\/\-]\d{4}$/;
    var valDate = $(this).val();
    if ( valDate.match( dateFormat )) {
      $(this).css("border","1px solid #cccccc","color", "#555555", "font-weight", "normal");
      var seperator1 = valDate.split('/');
      var seperator2 = valDate.split('-');

      if ( seperator1.length > 1 ) {
        var splitdate = valDate.split('/');
      } else if ( seperator2.length > 1 ) {
        var splitdate = valDate.split('-');
      }

      var dd = parseInt(splitdate[0]);
      var mm = parseInt(splitdate[1]);
      var yy = parseInt(splitdate[2]);
      var ListofDays = [31,28,31,30,31,30,31,31,30,31,30,31];

      if ( mm == 1 || mm > 2 ) {
        if ( dd > ListofDays[mm - 1] ) {
          $(this).val("");
          $(this).css("border","solid red 1px","color", "red", "font-weight", "bold");
          alert('Invalid Date! You used a date which does not exist in the known calender.');
          return false;
        }
      }

      if ( mm == 2 ) {
       var lyear = false;
        if ( (!(yy % 4) && yy % 100) || !(yy % 400) ){
          lyear = true;
        }

        if ( (lyear==false) && (dd>=29) ) {
          $(this).val("");
          $(this).css("border","solid red 1px","color", "red", "font-weight", "bold");
          alert('Invalid Date! You used Feb 29th for an invalid leap year');
          return false;
        }

        if ( (lyear==true) && (dd>29) ) {
          $(this).val("");
          $(this).css("border","solid red 1px","color", "red", "font-weight", "bold");
          alert('Invalid Date! You used a date greater than Feb 29th in a valid leap year');
          return false;
        }
     }
    } else {
      $(this).val("");
      $(this).css("border","solid red 1px","color", "red", "font-weight", "bold");
      alert('Date format was invalid! Please use format mm/dd/yyyy');
      return false;
    }
  };

  $('#from_date').change( checkDate );
  $('#to_date').change( checkDate );
});

###

Similar to Elian Ebbing answer, but support “\”, “/”, “.”, “-“, ” ” delimiters

function js_validate_date_dmyyyy(js_datestr)
{
    var js_days_in_year = [ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];
    var js_datepattern = /^(\d{1,2})([\.\-\/\\ ])(\d{1,2})([\.\-\/\\ ])(\d{4})$/;

    if (! js_datepattern.test(js_datestr)) { return false; }

    var js_match = js_datestr.match(js_datepattern);
    var js_day = parseInt(js_match[1]);
    var js_delimiter1 = js_match[2];
    var js_month = parseInt(js_match[3]);
    var js_delimiter2 = js_match[4];
    var js_year = parseInt(js_match[5]);                            

    if (js_is_leap_year(js_year)) { js_days_in_year[2] = 29; }

    if (js_delimiter1 !== js_delimiter2) { return false; } 
    if (js_month === 0  ||  js_month > 12)  { return false; } 
    if (js_day === 0  ||  js_day > js_days_in_year[js_month])   { return false; } 

    return true;
}

function js_is_leap_year(js_year)
{ 
    if(js_year % 4 === 0)
    { 
        if(js_year % 100 === 0)
        { 
            if(js_year % 400 === 0)
            { 
                return true; 
            } 
            else return false; 
        } 
        else return true; 
    } 
    return false; 
}

###

function fdate_validate(vi)
{
  var parts =vi.split('/');
  var result;
  var mydate = new Date(parts[2],parts[1]-1,parts[0]);
  if (parts[2] == mydate.getYear() && parts[1]-1 == mydate.getMonth() && parts[0] == mydate.getDate() )
  {result=0;}
  else
  {result=1;}
  return(result);
}

###

Moment is really a good one to resolve it. I don’t see reason to add complexity just to check date… take a look on moment : http://momentjs.com/

HTML :

<input class="form-control" id="date" name="date" onchange="isValidDate(this);" placeholder="DD/MM/YYYY" type="text" value="">

Script :

 function isValidDate(dateString)  {
    var dateToValidate = dateString.value
    var isValid = moment(dateToValidate, 'MM/DD/YYYY',true).isValid()
    if (isValid) {
        dateString.style.backgroundColor = '#FFFFFF';
    } else {
        dateString.style.backgroundColor = '#fba';
    }   
};

###

First string date is converted to js date format and converted into string format again, then it is compared with original string.

function dateValidation(){
    var dateString = "34/05/2019"
    var dateParts = dateString.split("/");
    var date= new Date(+dateParts[2], dateParts[1] - 1, +dateParts[0]);

    var isValid = isValid( dateString, date );
    console.log("Is valid date: " + isValid);
}

function isValidDate(dateString, date) {
    var newDateString = ( date.getDate()<10 ? ('0'+date.getDate()) : date.getDate() )+ '/'+ ((date.getMonth() + 1)<10? ('0'+(date.getMonth() + 1)) : (date.getMonth() + 1) )  + '/' +  date.getFullYear();
    return ( dateString == newDateString);
}

###

  1. Javascript

    function validateDate(date) {
        try {
            new Date(date).toISOString();
            return true;
        } catch (e) { 
            return false; 
        }
    }
    
  2. JQuery

    $.fn.validateDate = function() {
        try {
            new Date($(this[0]).val()).toISOString();
            return true;
        } catch (e) { 
            return false; 
        }
    }
    

returns true for a valid date string.

###

var date = new Date(date_string)

returns the literal 'Invalid Date' for any invalid date_string.

Note: Please see the comment’s below.

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