# RadCalendarDay Collection Editor The **RadCalendarDay Collection Editor** of the [ASP NET AJAX Calendar](https://www.telerik.com/products/aspnet-ajax/calendar.aspx) lets you define "special days" that the calendar control treats in a different way than the other days in its display. Special days can correspond to public holidays, vacation days, birthdays, and so on. To display the **RadCalendarDay Collection Editor**, locate the **SpecialDays** property in the properties pane for the **RadCalendar** control and click the ellipsis button. ![RadCalendarDay Collection editor](https://www.telerik.com/products/aspnet-ajax/documentation/assets/0aa2374a311fe6c2fd5f75058258b551/calendar_day_collection_editor.png) Use the **Add** and **Remove** buttons to add or remove special days. Select a special day and set its properties using the properties grid of the editor. The following table describes the properties of each special day: | Property | Description | | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | **Date** | The date that is set aside as a "special day". This value is interpreted based on the value of the **Repeatable** property. | | **IsDisabled** | When **true** , the special day is disabled in the calendar. | | **IsSelectable** | When **true** , the special day can be selected in the calendar. | | **IsSelected** | When **true** , the calendar starts up with the special day selected. | | **IsToday** | When **true** , the calendar defines the special day as "today". | | **IsWeekend** | When **true** , the special day is formatted as a weekend day. | | **ItemStyle** | A composite property that lets you assign the style properties of the special day so that it is visually distinct. | | **Repeatable** | Allows the special day definition to apply to several days in the calendar. Possible values are: **DayInMonth** - Only the day part of the **Date** property is used. The special day repeats every month on the same day; **Today** - The special day settings control the appearance and behavior of today's date. The value of the **Date** property is ignored; **DayAndMonth** - Only the month and day part of the **Date** property are used. The special day repeats every year on the same month and day; **WeekDayWeekNumberAndMonth** - Only the weekday (Mon, Tue, etc.), the week number, and the month are used. The special day repeats every year on a specific weekday in a specific week. Can be used for repeatable holidays that are on a different date each year. For instance Martin Luther King Jr. Day: every third Monday of January. Only the week number, the weekday (Mon, Tue, etc) and the month are used; **WeekAndMonth** - Only the day of the week and the month of the **Date** property are used. The special day repeats once a week on the same day for a specific month; **Week** - Only the day of the week of the **Date** property is used. The special day repeats every week on the same day; **None** - The special day occurs on the date specified by the **Date** property. It does not repeat. | | **TemplateID** | Identifies a dynamic day template that is used to display the special day. Dynamic day templates are defined using the [DayTemplate Collection Editor](https://www.telerik.com/products/aspnet-ajax/documentation/controls/calendar/design-time/daytemplate-collection-editor). | | **ToolTip** | A string that appears as a tooltip when the user hovers the mouse over the special day. | > note > If you set the **Repeatable** property for a special day to anything other than "None", you must either enable postbacks ( **AutoPostBack** = **True** ) or set the **EnableRepeatableDaysOnClient** property to **True** . Following is a sample illustrating the use of the **Repeatable** property: ```ASPNET ``` ## See Also * [RadCalendar Day Templates](https://www.telerik.com/products/aspnet-ajax/documentation/controls/calendar/templates/day-templates)