Get last day of month

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

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

lastdate: 30/09/2018



thank u in advance

Answer 1

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.

Answer 2

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 () {
            debugger;
            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); 
        });
    });
</script>

Best regards,
Dillion

Answer 3

User66371569 posted
Can u give me c# code if u can Thank alot

Answer 4

User-369506445 posted

hi

please try below code

DateTime today = DateTime.Today;
DateTime endOfMonth = new DateTime(today.Year,
                                   today.Month,
                                   DateTime.DaysInMonth(today.Year,today.Month));


            Response.Write(today.ToString() +"<br />");
            Response.Write(endOfMonth.ToString());

Result

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

Answer 5

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,
Dillion