Adds a specified time interval to a DateTimeOffset object that has a specified date and time, and yields a DateTimeOffset object that has new a date and time.
An object whose value is the sum of the values of dateTimeTz and timeSpan.
The DateTimeOffset.op_Addition(DateTimeOffset, TimeSpan) method defines the addition operation for DateTimeOffset values. It enables code such as the following:
code reference: System.DateTimeOffset.Operators#1
Languages that do not support custom operators and operator overloading can call the DateTimeOffset.Add(TimeSpan) method instead.