validate date format (y/m/d)

**vineet** · 12-10-2008, 06:13 AM

hi all

i want to use a function to format date in (yyyy/mm/dd).
The function is in my below code. how can i call this function onChange or onBlur so that when the user enters date it should alert if the date format is not valid.

Code:

<html>
<head>
<script language="javascript">
function validDate(y,m,d) 
{
if (y != parseInt(y,10) || m != parseInt(m,10)
|| d != parseInt(d,10)) return false;
m--;
var nd = new Date(y, m, d);
if (y == nd.getFullYear() && m == nd.getMonth()
&& d == nd.getDate()) return nd;
else return false;
} 
var customer_dob = validDate(year, month, day);
if (!customer_dob) 
{
alert('the date entered is invalid');
}
</script>
</head>
<body>
<form action="" method="get" name="advertise">
<input type="text" name="customer_dob" onChange="return validDate();" />
</form>
</body>

**Snookerman** · 12-10-2008, 09:39 AM

I found a script and rewrote it a bit to fit your requirements. It is a bit more advanced since it checks for leap years (even checks if they are divisible by 400). Here is the code:

HTML Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script language = "Javascript">
/**
 * DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */
// Declaring valid date character, minimum year and maximum year
// Changed by Snookerman into yyyy/mm/dd format
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 strYear=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strDay=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 : yyyy/mm/dd")
		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.txtDate
	if (isDate(dt.value)==false){
		dt.focus()
		return false
	}
    return true
 }

</script>
</head>
<body>
<form name="frmSample" method="post" action="" onSubmit="return ValidateForm()">
  <p>Enter a Date <font color="#CC0000"><b>(yyyy/mm/dd)</b></font> :
    <input type="text" name="txtDate" maxlength="10" size="15">
  </p>
  <p>
    <input type="submit" name="Submit" value="Submit">
  </p>
</form>
</body>
</html>

The original code is taken from here:

http://www.smartwebby.com/DHTML/date_validation.asp

I just changed it to your format, yyyy/mm/dd.

**vineet** · 12-10-2008, 12:44 PM

hi Snookerman

thanks a lot. it worked great. its really advanced script.

vineet

**Snookerman** · 12-10-2008, 01:54 PM

You're welcome! Make sure you mark this thread as Resolved.

**boogyman** · 12-10-2008, 05:14 PM

If you wanted just to check whether the date was entered in a valid format, you could use the following

Code:

<script type="javascript">
function checkDateFormat(field)
{
     /* What will be separating the values */
     var delimiter="/";
     /* Message to display if date format is incorrect */
     var msg = "The date you entered, appears to be in an incorrect format.";

     /********************************
     **   no need to edit beyond this line      **
     ********************************/
     var el = document.getElementById(field);

     /* checks if delimiter is regexp "wildcard" */
     if(/[-./].test(delimiter))
          delimiter = "\"+delimiter; 

     /* yyyy(delimiter)mm(delimiter)dd */
     var format = "/^[(19)|(20)]\d{2}"+delimiter+"[0-3]?[0-9]"+delimiter+"[0-3]?[0-9]$/";

     /* if error message already exists */
     var errMsg = document.getElementById('errMsg');
     if(errMsg);
         el.removeChild(errMsg);

     /* if doesn't follow format, writes error message */
     if(!format.test(el))
     {
          var p = document.createElement('p');
          p.id="errMsg";
          p.style.color = "#ff0000";
          p.style.font-weight = "bold";
          p.nodeValue = msg;
          el.appendChild(p);
     }
}
</script>

Code:

<input type="text" name="f_date" value="" onchange="javascript:checkDateFormat(this);">

If entered incorrectly, will produce the following with the example message
The date you entered, appears to be in an incorrect format.

**vineet** · 12-11-2008, 05:55 AM

hi boogyman

i think something is missing in your code.

i pasted it and half of the script is coming in original javascript code color and rest bottom half is coming in single blue colour.

vineet

**boogyman** · 12-11-2008, 02:11 PM

change

delimiter = "\"+delimiter;

to

Code:

delimiter = "\\"+delimiter;

the first backslash was escaping the end quotation

**vineet** · 12-11-2008, 03:01 PM

hi boogyman

This is complete code with correction which is giving error.

Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script language="javascript">
function checkDateFormat(field,delimiter)
{
     /* What will be separating the values */
     var delimiter="/";
     /* Message to display if date format is incorrect */
     var msg = "The date you entered, appears to be in an incorrect format.";

     /********************************
     **   no need to edit beyond this line      **
     ********************************/
     var el = document.getElementById(field);

     /* checks if delimiter is regexp "wildcard" */
     if(/[-./].test(delimiter))
         delimiter = "\\"+delimiter;
    
     var format = "/^[(19)|(20)]\d{2}"+delimiter+"[0-3]?[0-9]"+delimiter+"[0-3]?[0-9]$/";

     if(!format.test(el))
     {
          var p = document.createElement('p');
          p.style.color = "#ff0000";
          p.style.font-weight = "bold";
          p.nodeValue = msg;
          el.appendChild(p);
     }
}
</script>
</head>
<body>
<form name="form1" method="post" action="">
  <p>Enter a Date <font color="#CC0000"><b>(yyyy/mm/dd)</b></font> :
   <input type="text" name="f_date" value="" onchange="javascript:checkDateFormat(this);">
  </p>
  <p>
    <input type="submit" name="Submit" value="Submit">
  </p>
</form>
</body>
</html>

This is the error its giving

Code:

Line:20
Char:31
Error: Expected '/'
Code:0

its not alerting

vineet

**Snookerman** · 12-11-2008, 03:20 PM

Is the code I posted working for you?

**vineet** · 12-12-2008, 03:04 AM

Originally Posted by Snookerman

Is the code I posted working for you?

hi snookerman

yes the code you posted is working for me.

i m just telling boogyman that his code has some errors.

otherwise our issue has been resolved.

vineet

Thread: validate date format (y/m/d)

Thread Tools

Search Thread

validate date format (y/m/d)

date validation

date format

date format

Bookmarks

Bookmarks

Posting Permissions