[removed] how to validate dates in format MM-DD-YY

Question

I saw a potential answer here but that was for YYYY-MM-DD: JavaScript date validation

I modified the code code above for MM-DD-YYYY like so but I still can't get it to work:

String.prototype.isValidDate = function() 
{
     var IsoDateRe = new RegExp("^([0-9]{2})-([0-9]{2})-([0-9]{4})$");
     var matches = IsoDateRe.exec(this);
     if (!matches) return false;
     var composedDate = new Date(matches[3], (matches[1] - 1), matches[2]);
     return ((composedDate.getMonth() == (matches[1] - 1)) &&
      (composedDate.getDate() == matches[2]) &&
      (composedDate.getFullYear() == matches[3]));
}

How can I get the above code to work for MM-DD-YYYY and better yet MM/DD/YYYY?

Thanks.

Answer 1

what isn't working about it? here's a tested version:

String.prototype.isValidDate = function()   {

    var match   =   this.match(/^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/);
    var test    =   new Date(match[3], match[1] - 1, match[2]);
    return (
        (test.getMonth() == match[1] - 1) &&
        (test.getDate() == match[2]) &&
        (test.getFullYear() == match[3])
    );
}

var date = '12/08/1984'; // Date() is 'Sat Dec 08 1984 00:00:00 GMT-0800 (PST)'
alert(date.isValidDate() ); // true

Answer 2

You can simplify it somewhat by changing the first two lines of the function to this:

var matches = this.match(/^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/);

Or, just change the parameter to the RegExp constructor to be

^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$

Answer 3

pass this function to date with format //10-10-2012 and id of object.

function isValidDateFormat(date, id)
{
  var todayDate = new Date();
  var matches = /^(\d{2})[-\/](\d{2})[-\/](\d{4})$/.exec(date);

  if (matches == null)
  {
   if(date != '__-__-____')
    {
      alert('Please enter valid date');
    }
  }
  else
  {
    var day    = 31;
    var month  = 12;
    var b_date = date.split("-");
    if(b_date[0] <= day)
    {
      if(b_date[1] <= month)
      {
        if(b_date[2] >= 1900 && b_date[2] <= todayDate.getFullYear())
        {
          return true;
        }
        else
        {
          $("#"+id).val('');
          alert('Please enter valid Year'); 
        }         
      }
      else
      {
        $("#"+id).val('');
        alert('Please enter valid Month');    
      } 
    }
    else
    {
      alert('Please enter valid Day');
      $("#"+id).val('');  
    }
  }
}

Answer 4

function isValidDate(date) {
        var valid = true;

        date = date.replace('/-/g', '');

        var month = parseInt(date.substring(0, 2),10);
        var day   = parseInt(date.substring(2, 4),10);
        var year  = parseInt(date.substring(4, 8),10);

        if(isNaN(month) || isNaN(day) || isNaN(year)) return false;

        if((month < 1) || (month > 12)) valid = false;
        else if((day < 1) || (day > 31)) valid = false;
        else if(((month == 4) || (month == 6) || (month == 9) || (month == 11)) && (day > 30)) valid = false;
        else if((month == 2) && (((year % 400) == 0) || ((year % 4) == 0)) && ((year % 100) != 0) && (day > 29)) valid = false;
        else if((month == 2) && ((year % 100) == 0) && (day > 29)) valid = false;
        else if((month == 2) && (day > 28)) valid = false;

    return valid;
}

This checks for valid days in each month and for valid leap year days.

Answer 5

if (document.getElementById('expiryDay').value != test(match("/^([0-9]{2})\/([0-9]{2})$/"))){
     alert("Enter the date in two digit month flowed by two digits year \n");
}

Answer 6

<script language = "Javascript">
// Declaring valid date character, minimum year and maximum year
var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
    var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
    var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
    // February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
    for (var i = 1; i <= n; i++) {
        this[i] = 31
        if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
        if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
    var daysInMonth = DaysArray(12)
    var pos1=dtStr.indexOf(dtCh)
    var pos2=dtStr.indexOf(dtCh,pos1+1)
    var strDay=dtStr.substring(0,pos1)
    var strMonth=dtStr.substring(pos1+1,pos2)
    var strYear=dtStr.substring(pos2+1)
    strYr=strYear
    if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
    if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
    for (var i = 1; i <= 3; i++) {
        if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
    }
    month=parseInt(strMonth)
    day=parseInt(strDay)
    year=parseInt(strYr)
    if (pos1==-1 || pos2==-1){
        alert("The date format should be : dd/mm/yyyy")
        return false
    }
    if (strMonth.length<1 || month<1 || month>12){
        alert("Please enter a valid month")
        return false
    }
    if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
        alert("Please enter a valid day")
        return false
    }
    if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
        alert("Please enter a valid 4 digit year between "+minYear+" and "+maxYear)
        return false
    }
    if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
        alert("Please enter a valid date")
        return false
    }
return true
}

function ValidateForm(){
    var dt=document.frmSample.txtDateenter code here
    if (isDate(dt.value)==false){
        dt.focus()
        return false
    }
    return true
 }

</script>