HOWTO: Set the System Time

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, version 5.0
• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0

SUMMARY

The Win32 API offers the functionality to change the system time on the local machine. The change will take place immediately without the need for a reboot. Below is a code sample showing how to do this.

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. 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.