Question 85946 in ASP.NET Question posted in
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Issue time converting to 24 hours when i write time on asp.net web forms?

I working on with C# and ASP.NET webforms using Visual Studio 2022. I have an issue when trying to write time to a textbox.

When I try to write time 11:30 pm to a textbox, it is converted automatically to 23:30 – why was it converted?

I need time to working on 12 hours mode exactly as I write it.

So if I write 11:30 am, it must be shown as 11:30 am.

11:30 pm must be shown as 11:30 pm – here I have the issue that it is converted to 23:30 pm.

Expected result:

  • when I write 11:30 pm, it must show 11:30 pm

What do I do to solve this issue please?

webpage.cs

protected void txtFromTime_TextChanged(object sender, EventArgs e)
{
        var Transactiondate = Convert.ToDateTime(txtDate.Text);
        var dateonly = Transactiondate.ToString("dd/MM/yyyy");
       var eventDate = txtDate.Text + " " +Convert.ToDateTime(txtFromTime.Text).ToString("HH:mm");
      
        Label1.Text = eventDate.ToString();
}

web page.aspx

<form id="form1" runat="server">
    <div>
        <asp:Label ID="lblDate" runat="server" Text="Date" ></asp:Label>
        <asp:TextBox ID="txtDate" runat="server" TextMode="Date" AutoPostBack = "True" OnTextChanged="txtDate_TextChanged"></asp:TextBox>
        <asp:Label ID="lblFromTime" runat="server" Text="FromTime"></asp:Label>
        <asp:TextBox ID="txtFromTime" runat="server" TextMode="Time" AutoPostBack = "True"  OnTextChanged="txtFromTime_TextChanged"></asp:TextBox>
    </div>
    <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</form>

picture issue

Image for issue time

Tags:

2

Answers


  1. 0

    It’s because you used upper-case HH instead of lower-case hh in the format string. You also need the AM/PM indicator:

    hh:mm tt

    This is well-documented:

    https://learn.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings

    Unfortunately, right now this always results in an uppercase indicator, so you’ll see 11:30 PM. If you really need to see 11:30 pm you need to correct it with normal string manipulation.

    I’d like to see the t ("t"ime of day) specifiers enhanced, such that lowercase t is a lowercase indicator and uppercase T is an uppercase indicator, along with a mechanism to infer the case from the system’s datetime format. I suspect the reason this has not happened is a certain important time format uses a literal T to separate the date and time portions of the string.

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  2. 0

    why not consider just one text box, and use textmode=

    So, say this text box:

            <asp:TextBox ID="TextBox1" runat="server"
            TextMode="DateTimeLocal">
        </asp:TextBox>

    You then get/see this:

    enter image description here

    In other words, you have one text box – it will have both date and time for you.

    About the only thing I don’t like, is tab key does not select, you have to hit enter key.

    but, it also allows in-line editing if you don’t want to use the picker.

    Hence this:

    enter image description here

    And if you enter (without the picker), then you have to use arrow keys to move to the next part. Again, I don’t find this 100% intuitive.

    However, you can drop in 2 controls, and feed it the "one" date time variable. You feed using "iso" date format, but it will take on your local settings.

    So, say this markup:

            <h4>Enter Date</h4>
        <asp:TextBox ID="txtDate" runat="server"
            TextMode="Date">
        </asp:TextBox>

        <h4>Enter Time</h4>
        <asp:TextBox ID="txtTime" runat="server"
            TextMode="Time">
        </asp:TextBox>

    And code to load:

                DateTime dtStart = DateTime.Now;

            txtDate.Text = dtStart.ToString(@"yyyy-MM-dd");
            txtTime.Text = dtStart.ToString(@"HH:mm");

    NOTE close above, I feed the time a 24 hour format, but it does display in 12 hour format.

    and now we get/see this:

    enter image description here

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