The RadDateSelector control allows the user to get the value selected by the user in two ways:
Getting the Value as DateTime
In order to get the selected date as a DateTime you have to use the SelectedValue property of the RadDateSelector
DateTime value = this.radDateSelector.SelectedValue;
Getting the Value as String
In order to get the selected value as String you have to use the ValueString property of the RadDateSelector control.
string stringValue = this.radDateSelector.ValueString;
By default, the ValueString property returns a string representation of the currently selected value
formatted according to the default culture of the phone or the one explicitly set to the control by using the Culture property.