The Date Time Collection Editor allows the user to add/remove selected calendar dates or add/remove disabled dates in C1Calendar.

To access the DateTime Collection Editor for Selected Dates:

1. Right-click on the C1Calendar control and select Properties from its context menu.
2. In C1Calendar's Properties window, select the SelectedDates property.
3. Click on the ellipsis button next to the SelectedDates property to expose the Date Time Collection Editor.

To access the DateTime Collection Editor for Disabled Dates:

1. Right-click on the C1Calendar control and select Properties from its context menu.
2. In C1Calendar's Properties window, select the DisabledDates property.
3. Click on the ellipsis button next to the DisabledDates property to expose the C1Date Collection Editor.