HOWTO: Set the System Time

ID: Q154009


The information in this article applies to:
  • Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0
  • Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 32-bit only, for Windows, version 4.0


SUMMARY

The Win32 SetSystemTime API function offers the functionality to change the system time on the local machine. The change will take place immediately without the need for a reboot. This article illustrates how to create a sample project that sets the system time using the SetSystemTime function.


MORE INFORMATION

  1. Start a new project in Visual Basic. Form1 is created by default.


  2. Add the following code to the General Declarations section of Form1:
    
          Option Explicit
    
          Private Type SYSTEMTIME
            wYear As Integer
            wMonth As Integer
            wDayOfWeek As Integer
            wDay As Integer
            wHour As Integer
            wMinute As Integer
            wSecond As Integer
            wMilliseconds As Integer
          End Type
    
          Private Declare Function SetSystemTime Lib "kernel32" (lpSystemTime _
            As SYSTEMTIME) As Long
    
          Private Sub Form_Load()
            Dim lReturn As Long
            Dim lpSystemTime As SYSTEMTIME
            lpSystemTime.wYear = 1996
            lpSystemTime.wMonth = 6
            lpSystemTime.wDayOfWeek = 5
            lpSystemTime.wDay = 28
            lpSystemTime.wHour = 9
            lpSystemTime.wMinute = 42
            lpSystemTime.wSecond = 0
            lpSystemTime.wMilliseconds = 0
            lReturn = SetSystemTime(lpSystemTime)
          End Sub
     


  3. Run the project by pressing the F5 key. Check the system time and date in the Control Panel or on the system. Do the same in Windows 95 or Windows 98. It should have changed to reflect the settings from the code.



REFERENCES

The SYSTEMTIME Type structure is as follows:


   WYear           Integer-The current year.
   WMonth          Integer-The current month. January is 1.
   WDayOfWeek      Integer-The current day of the week. Sunday is 0.
   WDay            Integer-The current day of the month.
   WHour           Integer-The current hour.
   wMinute         Integer-The current minute.
   wSecond         Integer-The current second.
   wMilliseconds   Integer-The current millisecond. 

To change the system time on a Win32 platform from 16-bit Visual Basic, you would have to create a DLL that does a generic thunk to the 32-bit API SetSystemTime.

For more information, please see article Q104009 on the Microsoft Developer Network (MSDN) and the article outline in the Microsoft Systems Journal (MSJ) for June 1994.

Additional query words: kbVBp kbVBp500 kbVBp400 kbVBp600 KBWIN32SDK kbAPI kbDSupport kbdsd

Keywords : kbGrpVB
Version :
Platform : NT WINDOWS
Issue type : kbhowto


Last Reviewed: January 5, 2000
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