Check if a date is valid.

itbarota · #1 (**permalink**) 03-20-2008, 09:10 PM

Hi all

Can anyone tell me how can i check if a date is valid.

Thanks in advance...

Pvinothkumar · #2 (**permalink**) 03-20-2008, 09:12 PM

Hi all....

//Put the following in <HEAD> section:
<script language="JavaScript"><
function checkDate(theDate) {
// If the value is not blank, validate the date.
// using isNaN (is not a number) and date parse.
// If the date is invalid, give the user an alert
// message, set the form focus to the date field.
// and return false. If it's valid then return true.

if (theDate!= "") {
if (isNaN(Date.parse(theDate))) {
alert("Please enter yourDate in mm/dd/yy format.");
return false;
} else {
return true;
}
}
}
</script>

Thanks...

KiruthikaSambandam · #3 (**permalink**) 03-21-2008, 08:21 PM

Javascript Date Validation - mm/dd/yyyy format

<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 strMonth=dtStr.substring(0,pos1)
var strDay=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 : mm/dd/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.txtDate
if (isDate(dt.value)==false){
dt.focus()
return false
}
return true
}

</script>

CodyBane · #4 (**permalink**) 04-10-2008, 03:04 PM

Simple google search yields many results:

Code:

<!-- TWO STEPS TO INSTALL VALIDATE DATE:

  1.  Copy the coding into the HEAD of your HTML document
  2.  Add the last code into the BODY of your HTML document  -->

<!-- STEP ONE: Paste this code into the HEAD of your HTML document  -->

<HEAD>

<SCRIPT LANGUAGE="JavaScript">

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Original:  Torsten Frey (tf@tfrey.de) -->
<!-- Web Site:  http://www.tfrey.de -->

<!-- Begin
function check_date(field){
var checkstr = "0123456789";
var DateField = field;
var Datevalue = "";
var DateTemp = "";
var seperator = ".";
var day;
var month;
var year;
var leap = 0;
var err = 0;
var i;
   err = 0;
   DateValue = DateField.value;
   /* Delete all chars except 0..9 */
   for (i = 0; i < DateValue.length; i++) {
	  if (checkstr.indexOf(DateValue.substr(i,1)) >= 0) {
	     DateTemp = DateTemp + DateValue.substr(i,1);
	  }
   }
   DateValue = DateTemp;
   /* Always change date to 8 digits - string*/
   /* if year is entered as 2-digit / always assume 20xx */
   if (DateValue.length == 6) {
      DateValue = DateValue.substr(0,4) + '20' + DateValue.substr(4,2); }
   if (DateValue.length != 8) {
      err = 19;}
   /* year is wrong if year = 0000 */
   year = DateValue.substr(4,4);
   if (year == 0) {
      err = 20;
   }
   /* Validation of month*/
   month = DateValue.substr(2,2);
   if ((month < 1) || (month > 12)) {
      err = 21;
   }
   /* Validation of day*/
   day = DateValue.substr(0,2);
   if (day < 1) {
     err = 22;
   }
   /* Validation leap-year / february / day */
   if ((year % 4 == 0) || (year % 100 == 0) || (year % 400 == 0)) {
      leap = 1;
   }
   if ((month == 2) && (leap == 1) && (day > 29)) {
      err = 23;
   }
   if ((month == 2) && (leap != 1) && (day > 28)) {
      err = 24;
   }
   /* Validation of other months */
   if ((day > 31) && ((month == "01") || (month == "03") || (month == "05") || (month == "07") || (month == "08") || (month == "10") || (month == "12"))) {
      err = 25;
   }
   if ((day > 30) && ((month == "04") || (month == "06") || (month == "09") || (month == "11"))) {
      err = 26;
   }
   /* if 00 ist entered, no error, deleting the entry */
   if ((day == 0) && (month == 0) && (year == 00)) {
      err = 0; day = ""; month = ""; year = ""; seperator = "";
   }
   /* if no error, write the completed date to Input-Field (e.g. 13.12.2001) */
   if (err == 0) {
      DateField.value = day + seperator + month + seperator + year;
   }
   /* Error-message if err != 0 */
   else {
      alert("Date is incorrect!");
      DateField.select();
	  DateField.focus();
   }
}
//  End -->
</script>

</HEAD>

Now this code is less than ideal in terms of validation, but it gets the point across

Code:

<!-- STEP TWO: Copy this code into the BODY of your HTML document  -->

<BODY>

<CENTER>
<FORM name="datecheck">
<TABLE border="0" width="60%">
    <TR>
  	<TD>
    Enter Date (Use European format shown at right)<P>
  	<INPUT type="text" name=testdat size='10' maxlength="10" onblur="check_date(this)">
  	<INPUT type= "submit" name="button" value="Press to Validate"><p>
	(Date is validated after leaving the field.)
    </TD>
    <TD>
  	<b>ddmmyy</b> (171201)   or <BR>
  	<b>ddmmyyyy</b> (17122001) or <BR>
  	<b>ddXmmXyy</b> (17-12-01 or 17y12q01 ... ) or <BR>
  	<b>ddXmmXyyyy</b> (17.12.2001 or 17,12,2001 ...) <br>
  	where "X" is any sign not in 0..9, i.e. "-" or "/"<p>
  	</TD>
    </TR>
</TABLE>
</FORM>
</CENTER>


<p><center>
<font face="arial, helvetica" size"-2">Free JavaScripts provided<br>
by <a href="http://javascriptsource.com">The JavaScript Source</a></font>
</center><p>

<!-- Script Size:  3.77 KB -->

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DiscussWeb IT Community - Technical Support and Technology Discussions	This thread	Refback	03-21-2008 08:15 PM

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