DateTime.AddDays Method
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Returns a new DateTime that adds the specified number of days to the value of this instance.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Function AddDays ( _
value As Double _
) As DateTime
public DateTime AddDays(
double value
)
Parameters
- value
Type: System.Double
The number of whole and fractional days to add. This value can be positive or negative.
Return Value
Type: System.DateTime
An object whose value is the sum of the date and time represented by this instance and the number of days represented by value.
Exceptions
| Exception | Condition |
|---|---|
| ArgumentOutOfRangeException | The resulting DateTime is earlier than DateTime.MinValue or later than DateTime.MaxValue. |
Remarks
This method does not change the value of this DateTime. Instead, a new DateTime is returned whose value is the result of this operation.
The fractional part of value is the fractional part of a day. For example, 4.5 is equivalent to 4 days, 12 hours, 0 minutes, 0 seconds, 0 milliseconds, and 0 ticks.
The value parameter is rounded to the nearest millisecond.
Examples
The following example demonstrates the AddDays method.
' Calculate what day of the week is 36 days from this instant.
Dim today As System.DateTime
Dim answer As System.DateTime
today = System.DateTime.Now
answer = today.AddDays(36)
outputBlock.Text += String.Format("{0:dddd}", answer) + vbCrLf
// Calculate what day of the week is 36 days from this instant.
System.DateTime today = System.DateTime.Now;
System.DateTime answer = today.AddDays(36);
outputBlock.Text += String.Format("{0:dddd}", answer) + "\n";
Version Information
Silverlight
Supported in: 5, 4, 3
Silverlight for Windows Phone
Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0
XNA Framework
Supported in: Xbox 360, Windows Phone OS 7.0
Platforms
For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.