I am using AjaxControlToolkit for .Net 4.0
I am having a form with textbox that displays/accepts date and time in MM/DD/YYYY HH:MM format i.e. US date format with 24 hour time format.
I have used TextBox with MaskedEditExtender and the MaskedEditValidator. Please look at the following code -
<p>
        First Date Time : 
        <asp:TextBox ID="txtDateTime1" runat="server"></asp:TextBox>
        <asp:MaskedEditExtender ID="mskDateTime1" runat="server" 
            Mask="99/99/9999 99:99" MaskType="DateTime" TargetControlID="txtDateTime1" 
            UserTimeFormat="TwentyFourHour">
        </asp:MaskedEditExtender>
        <asp:MaskedEditValidator ID="mskValDateTime1" runat="server" 
            ControlExtender="mskDateTime1" ControlToValidate="txtDateTime1" 
            IsValidEmpty="False"></asp:MaskedEditValidator>
    </p>
    <p>
        Second Date Time : 
        <asp:TextBox ID="txtDateTime2" runat="server"></asp:TextBox>
        <asp:MaskedEditExtender ID="mskDateTime2" runat="server" 
            Mask="99/99/9999 99:99" MaskType="DateTime" TargetControlID="txtDateTime2" 
            UserTimeFormat="TwentyFourHour">
        </asp:MaskedEditExtender>
        <asp:MaskedEditValidator ID="mskValDateTime2" runat="server" 
            ControlExtender="mskDateTime2" ControlToValidate="txtDateTime2" 
            IsValidEmpty="False"></asp:MaskedEditValidator>
    </p>
For showing the dates in above format i am using format in ToString() as given below -
protected void Page_Load(object sender, EventArgs e)
        {
            txtDateTime1.Text = DateTime.Now.ToString("MM/dd/yyyy HH:mm");
            txtDateTime2.Text = DateTime.Now.ToString("MM/dd/yyyy HH:mm");
        }
The date and time is displayed correctly but when the focus goes out of the textboxes the time changes.
I don't know why this happening.
Please look at the following snapshots -
A) Originally 

B) Changed after focus out

Can anybody help me out solve this issue.
Do provide better ideas if any.
Thanks for sharing your wisdom.
 
                        
Finally, i have reply my own question as not received any replies from developers. I found it is actually an issue with MaskEditExtender. You can check this discussion.