[This documentation is for preview only, and is subject to change in later releases. Blank topics are included as placeholders.]
Returns a new DateTime that adds the specified number of hours to the value of this instance.
Assembly: mscorlib (in mscorlib.dll)
- Type: System..::..Double
A number of whole and fractional hours. The val parameter can be negative or positive.
Return ValueType: System..::..DateTime
An object whose value is the sum of the date and time represented by this instance and the number of hours represented by val.
This method does not change the value of this DateTime. Instead, it returns a new DateTime whose value is the result of this operation. The Kind property of the returned DateTime object is the same as that of val.
The fractional part of val is the fractional part of an hour. For example, 4.5 is equivalent to 4 hours, 30 minutes, 0 seconds, 0 milliseconds, and 0 ticks.
The val parameter is rounded to the nearest millisecond.
Converting time intervals of less than an hour to a fraction can involve a loss of precision if the result is a non-terminating repeating decimal. (For example, one minute is 0.016667 of an hour.) If this is problematic, you can use the Add method, which enables you to specify more than one kind of time interval in a single method call and eliminates the need to convert time intervals to fractional parts of an hour.
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see dd66cd4c-b087-415f-9c3e-94e3a1835f74.