OL97: OL98: SetColumns Returns Incorrect Times When Used with Tasks (219034)
The information in this article applies to:
This article was previously published under Q219034 SYMPTOMS
When using the SetColumns method to retrieve dates or times from tasks, the times may not accurately reflect what is stored in the task.
CAUSE
With the exception of tasks, all dates in Outlook are stored in Coordinated Universal Time (UTC), also known as Greenwich Mean Time (GMT). However, tasks store dates in local time. The SetColumns method always converts the retrieved time into local time, therefore causing the times to be offset.
WORKAROUNDMethod 1: Do Not Use SetColumns
Do not use the SetColumns method to retrieve dates with tasks. In most cases this adversely affects your solution's performance.
Method 2: Retrieve and Use an OffSetNOTE: If you are using Visual Basic Scripting Edition (VBScript), you cannot access the system registry and this workaround does not apply.
If you are using Visual Basic or Visual Basic for Applications, programmatically get the local time zone information from the computer running your application. This information is stored in the following location in the registry:
HKEY_Local_Machine\SYSTEM\CurrentControlSet\Control\TimeZoneInformation
The Bias value specifies the current bias, in minutes, for local time translation on the computer. The bias is the difference, in minutes, between local time and UTC. Use this value to correct the time retrieved using the SetColumns method.
STATUSMicrosoft has confirmed that this is a bug in the Microsoft products that are listed at the beginning of this article. MORE INFORMATION
The Date type is implemented as a floating-point value, measuring days from midnight, December, 30 1899. To interpret the time portion, take the absolute value of the fractional part of the number. Since the bias is measured in minutes however, you must divide the bias by the number of minutes in a day (1440) in order to perform the conversion. The formula is:
local time + (Bias / 1440 ) = UTC
For example, the Date value of a task to be started February 14, 1999 (UTC) should be 36205.0. However, if your application is run on a computer in New York, the Date value (local time) may be 36204.7916667 (February 13, 1999 7:00 P.M.). To perform the conversion, find the computer's bias (from the registry), which is 0x0000012c (300 minutes). Using this in the formula, we have:
local time + (Bias / 1440 ) = UTC
36204.7916667 + (300/1440) = 36205.0
(February 13, 1999 7:00 PM + 5hrs) = February 14, 1999 0:00am
For more information about using Visual Basic to retrieve values from the registry, please see the following article in the Microsoft Knowledge Base: 145679 HOWTO: Use the Registry API to Save and Retrieve Setting
Steps to Reproduce the Problem:Microsoft provides programming examples for illustration only, without warranty either
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- Create a new task in the default tasks folder.
- Set the Subject to New Task.
- Set the Start date to any date and time.
- Save the task.
- Enter the following automation code into Visual Basic or Visual Basic for Applications:
Private Sub Command1_Click()
Dim OutApp As Outlook.Application
Dim oNameSpace As Outlook.NameSpace
Dim oFolder As Outlook.MAPIFolder
Dim oItems As Outlook.Items
Dim oTask As Outlook.TaskItem
Set OutApp = New Outlook.Application
Set oNameSpace = OutApp.GetNamespace("MAPI")
Set oFolder = oNameSpace.GetDefaultFolder(olFolderTasks)
Set oItems = oFolder.Items
Set oTask = oItems("New Task")
MsgBox CDbl(oTask.StartDate)
oItems.SetColumns "StartDate"
Set oTask2 = oItems("New Task")
MsgBox CDbl(oTask2.StartDate)
End Sub
- Add a reference to the Microsoft Outlook 98 Object Model.
- Run the code.
REFERENCES
For more information about creating solutions with Microsoft Outlook 98,
please see the following articles in the Microsoft Knowledge Base: 180826 OL98: Resources for Custom Forms and Programming
182349 OL98: Questions About Custom Forms and Outlook Solutions
Modification Type: | Major | Last Reviewed: | 5/13/2002 |
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Keywords: | kbbug kbProgramming KB219034 |
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