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## ASP.NET Calendar VisibleDate Property The `VisibleDate` property is a member of the ASP.NET WebControl `Calendar` class. It is used to get or set the date that determines which month is currently displayed on the Calendar control. --- ## Definition and Usage By default, when a Calendar control is rendered for the first time, it displays the month containing the current system date (today's date). By using the `VisibleDate` property, you can programmatically override this behavior to force the calendar to display a specific month and year. ### Key Characteristics: * **Month Navigation:** The calendar will display the entire month containing the date assigned to `VisibleDate`. * **Difference from SelectedDate:** Setting `VisibleDate` only changes the *viewed* month; it does not select the date or change the `SelectedDate` property. * **Dynamic Updates:** If the user clicks the next or previous month navigation buttons, this property automatically updates to reflect the first day of the newly displayed month. --- ## Syntax ```syntax ``` Or programmatically in code-behind: ```csharp // C# Syntax Calendar1.VisibleDate = new DateTime(2023, 10, 1); ``` ```vb ' VB.NET Syntax Calendar1.VisibleDate = DateValue("01-Oct-2023") ``` --- ## Code Examples ### Example 1: Setting the Visible Date Programmatically (VB.NET) The following example demonstrates how to set the `VisibleDate` property to October 1, 2007, when the page loads. This forces the calendar to display October 2007 instead of the current month. ```html

``` ### Example 2: Setting the Visible Date Programmatically (C#) Here is the equivalent implementation using C# in the code-behind: ```html

``` --- ## Important Considerations 1. **Default Value:** If `VisibleDate` is not explicitly set, its default value is `DateTime.MinValue`. When it is set to `DateTime.MinValue`, the calendar automatically defaults to displaying the month containing the current system date (`DateTime.Today`). 2. **State Persistence:** The `VisibleDate` property is saved in the page's ViewState. If you modify it during a postback, the calendar will update its view accordingly. 3. **Synchronization with SelectedDate:** If you want the calendar to open to a pre-selected date, you should set both `SelectedDate` and `VisibleDate` to the same date value. If you only set `SelectedDate`, the calendar might not automatically scroll to display that month unless `VisibleDate` is also updated or left at its default.