[RESOLVED]Return last date in month

I have an asp.net web page that I need a javascript function to return the last day of a month based on a date passed from a TextBox.  For example, if I pass 10/10/2014 I want it to return 10/31/2014.  How can I do that in javascript?  Thanks.

You could use a function like this :

function GetLastDayOfMonth(date){
   // Attempt to parse the Date passed in
   var currentDate = new Date(date);
  
   // Get the last day of that month
   var targetDate = new Date(currentDate.getFullYear(), currentDate.getMonth() + 1, 0);
   
   return targetDate;
}

You can see a working example here, which would return a Date object of "October 31st 2014" provided the input your example shows (10/10/2014). If you needed to actually output your Date in that format,
you would just need to adjust it slightly to handle the formatting :

function GetLastDayOfMonth(date){
  
   // Attempt to parse the Date passed in
   var currentDate = new Date(date);
  
   // Get the last day of that month
   var targetDate = new Date(currentDate.getFullYear(), currentDate.getMonth() + 1, 0);
   
   // Outputs your date as a string in the format : "MM/dd/yyyy"
   return ('0' + (targetDate.getMonth()+1)).slice(-2) + '/' + ('0' + (targetDate.getDate())).slice(-2) + '/' + targetDate.getFullYear();
}

An example with formatting can be seen
here
.

Perfect! Thanks.

One other question.  When I use this js function on a TextBox with a CalendarExtender control and click on it after setting the value from the function, it does not show the new month but rather the old month before the change.

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