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DateTimeOffset.AddHours(Double) Method

  • Reference

Definition

Namespace:
System
Assembly:
System.Runtime.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll
Source:
DateTimeOffset.cs
Source:
DateTimeOffset.cs
Source:
DateTimeOffset.cs

Returns a new DateTimeOffset object that adds a specified number of whole and fractional hours to the value of this instance.

public:
 DateTimeOffset AddHours(double hours);
public DateTimeOffset AddHours (double hours);
member this.AddHours : double -> DateTimeOffset
Public Function AddHours (hours As Double) As DateTimeOffset

Parameters

hours
Double

A number of whole and fractional hours. The number can be negative or positive.

Returns

DateTimeOffset

An object whose value is the sum of the date and time represented by the current DateTimeOffset object and the number of hours represented by hours.

Exceptions

ArgumentOutOfRangeException

The resulting DateTimeOffset value is less than DateTimeOffset.MinValue.

-or-

The resulting DateTimeOffset value is greater than DateTimeOffset.MaxValue.

Examples

The following example uses the AddHours method to list the start times of work shifts for a particular week at an office that has two eight-hour shifts per day.

const int SHIFT_LENGTH = 8;

DateTimeOffset startTime = new DateTimeOffset(2007, 8, 6, 0, 0, 0,
                     DateTimeOffset.Now.Offset);
DateTimeOffset startOfShift = startTime.AddHours(SHIFT_LENGTH);

Console.WriteLine("Shifts for the week of {0:D}", startOfShift);
do
{
   // Exclude third shift
   if (startOfShift.Hour > 6)
      Console.WriteLine("   {0:d} at {0:T}", startOfShift);

   startOfShift = startOfShift.AddHours(SHIFT_LENGTH);
} while (startOfShift.DayOfWeek != DayOfWeek.Saturday &
           startOfShift.DayOfWeek != DayOfWeek.Sunday);
// The example produces the following output:
//
//    Shifts for the week of Monday, August 06, 2007
//       8/6/2007 at 8:00:00 AM
//       8/6/2007 at 4:00:00 PM
//       8/7/2007 at 8:00:00 AM
//       8/7/2007 at 4:00:00 PM
//       8/8/2007 at 8:00:00 AM
//       8/8/2007 at 4:00:00 PM
//       8/9/2007 at 8:00:00 AM
//       8/9/2007 at 4:00:00 PM
//       8/10/2007 at 8:00:00 AM
//       8/10/2007 at 4:00:00 PM

let shiftLength = 8

let startTime = DateTimeOffset(2007, 8, 6, 0, 0, 0, DateTimeOffset.Now.Offset)
let mutable startOfShift = startTime.AddHours shiftLength

printfn $"Shifts for the week of {startOfShift:D}"
while startOfShift.DayOfWeek <> DayOfWeek.Saturday &&
      startOfShift.DayOfWeek <> DayOfWeek.Sunday do
    // Exclude third shift
    if startOfShift.Hour > 6 then
        printfn $"   {startOfShift:d} at {startOfShift:T}"

    startOfShift <- startOfShift.AddHours shiftLength

// The example produces the following output:
//
//    Shifts for the week of Monday, August 06, 2007
//       8/6/2007 at 8:00:00 AM
//       8/6/2007 at 4:00:00 PM
//       8/7/2007 at 8:00:00 AM
//       8/7/2007 at 4:00:00 PM
//       8/8/2007 at 8:00:00 AM
//       8/8/2007 at 4:00:00 PM
//       8/9/2007 at 8:00:00 AM
//       8/9/2007 at 4:00:00 PM
//       8/10/2007 at 8:00:00 AM
//       8/10/2007 at 4:00:00 PM

Const SHIFT_LENGTH As Integer = 8

Dim startTime As New DateTimeOffset(#8/6/2007 12:00:00AM#, _
                     DateTimeOffset.Now.Offset)
Dim startOfShift As DateTimeOffset = startTime.AddHours(SHIFT_LENGTH)

Console.WriteLine("Shifts for the week of {0:D}", startOfShift)                           
Do 
   ' Exclude third shift
   If startOfShift.Hour > 6 Then _
      Console.WriteLine("   {0:d} at {0:T}", startOfShift)

   startOfShift = startOfShift.AddHours(SHIFT_LENGTH)
Loop While startOfShift.DayOfWeek <> DayOfWeek.Saturday And _
           startOfShift.DayOfWeek <> DayOfWeek.Sunday
          
' The example produces the following output:
'
'    Shifts for the week of Monday, August 06, 2007
'       8/6/2007 at 8:00:00 AM
'       8/6/2007 at 4:00:00 PM
'       8/7/2007 at 8:00:00 AM
'       8/7/2007 at 4:00:00 PM
'       8/8/2007 at 8:00:00 AM
'       8/8/2007 at 4:00:00 PM
'       8/9/2007 at 8:00:00 AM
'       8/9/2007 at 4:00:00 PM
'       8/10/2007 at 8:00:00 AM
'       8/10/2007 at 4:00:00 PM

Remarks

The fractional part of the hours parameter is the fractional part of an hour. For example, 4.5 is equivalent to 4 hours, 30 minutes, 0 seconds, 0 milliseconds.

In .NET 6 and earlier versions, the hours parameter is rounded to the nearest millisecond. In .NET 7 and later versions, the full Double precision of the hours parameter is used. However, due to the inherent imprecision of floating point math, the resulting precision will vary.

Note

This method returns a new DateTimeOffset object. It does not modify the value of the current object by adding hours to its date and time.

Because a DateTimeOffset object does not represent the date and time in a specific time zone, the AddHours method does not consider a particular time zone's adjustment rules when it performs date and time arithmetic.

Converting time intervals of less than an hour to a fraction can involve a loss of precision. (For example, one minute is 0.01666 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.

Applies to

See also