true, if a date and time format is applied to the cell; otherwise, false.
A date and time format is automatically applied to a cell in the following cases.
- A cell's CellRange.Value property is set to a DateTime object.
- A cell's CellRange.Value property is set to an object returned by the CellValue.FromDateTime method.
- A date and time value or a formula that returns a date and time value is entered into a cell via the SpreadsheetControl's UI.
To apply a date and time format to a cell explicitly, assign the corresponding format code to the Formatting.NumberFormat property of the cell object. For details, see the How to: Specify Number or Date Format for Cell Content example.