Get last day of month RRS feed

  • Question

  • User66371569 posted
    Hi there
    I have textbox for inserting date called startdate

    i want when user insert date get last day of month in another textbox

    startdate: 23/09/2018 "my format is dd/mm/yyyy"

    lastdate: 30/09/2018

    thank u in advance
    Sunday, September 23, 2018 4:06 PM

All replies

  • User409696431 posted

    I assume you know how to parse that for the integer month and year.  Use DateTime.DaysInMonth(intyear, intmonth) https://docs.microsoft.com/en-us/dotnet/api/system.datetime.daysinmonth?view=netframework-4.7.2  to get the last day of that month (it returns an integer). You can then use that to construct the ending date in the format you want.

    Monday, September 24, 2018 2:10 AM
  • User-271186128 posted

    Hi Sir,

    You could use date methods to get the last day of month, code as below:

    <input type="text" id="startdate" value="" />
    <input type="text" id="enddate" value="" />
    <script src="~/lib/jquery/dist/jquery.js"></script>
    <script type="text/javascript">
        $(function () {
            $("#startdate").change(function () {
                var startdate = $(this).val(); 
                var datenum = startdate.split('/');  //dd/mm/yyyy
                var date = new Date(parseInt(datenum[2]), parseInt(datenum[1]), 0);
                var yy = date.getFullYear(); //get year
                var mm = date.getMonth() + 1; //get month
                var day = date.getDate();  //get the day of the month
                $("#enddate").val(day + "/" + mm + "/" + yy); 

    Best regards,

    Monday, September 24, 2018 3:20 AM
  • User66371569 posted
    Can u give me c# code if u can Thank alot
    Monday, September 24, 2018 4:03 AM
  • User-369506445 posted


    please try below code

    DateTime today = DateTime.Today;
    DateTime endOfMonth = new DateTime(today.Year,
                Response.Write(today.ToString() +"<br />");


    9/24/2018 12:00:00 AM
    9/30/2018 12:00:00 AM

    Monday, September 24, 2018 5:14 AM
  • User-271186128 posted

    Hi sir, 

    You could refer to the following code:

                <asp:TextBox ID="StartDate" runat="server" AutoPostBack="true" OnTextChanged="StartDate_TextChanged"></asp:TextBox>
                <asp:TextBox ID="LastDate" runat="server"></asp:TextBox>

    and code behind:

            protected void StartDate_TextChanged(object sender, EventArgs e)
                var numlist = StartDate.Text.Split('/'); //get the number list.
                //base on the startdate to new date.
                DateTime date = new DateTime(Convert.ToInt32(numlist[2]), Convert.ToInt32(numlist[1]) + 1, 1);
                date = date.AddDays(-1); //get the last day
                LastDate.Text = date.ToString("dd/MM/yyyy");

    In my opinion, I suggest you could use jquery to get the last date, because there is no need to send a request to server side to get the last date.

    Best regards,

    Monday, September 24, 2018 8:03 AM