How To Retrieve Elapsed Time Since Windows Started

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, version 3.0

SUMMARY

The Windows API provides two functions (GetCurrentTime and GetTickCount) that return the number of milliseconds that have elapsed since Windows started. The GetTickCount function is identical in function to the GetCurrentTime function. However, GetTickCount should be used instead of GetCurrentTime because the name more closely matches its function.

MORE INFORMATION

GetTickCount returns the number of milliseconds since Windows started, and it resets to zero (0) if Windows is run continuously for approximately 49 days.

After the value has been retrieved, you can convert it to minutes and seconds and display it in the hh:mm:ss format.

Step-by-Step Example

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

2. Add a command button (Command1) to the form.

3. Add the following to the General Declarations Section of Form1:

      Declare Function GetTickCount Lib "User" () As Long
   
   

4. Add the following code to the Command1_Click event:

      Sub Command1_Click ()
         Dim Count As Long
         Dim Days As Integer, Hours As Double
         Dim Minutes As Double, Seconds As Double
         Dim Message As String
   
         ' Get milliseconds since windows started
         Count = GetTickCount()
   
         ' Convert to Seconds
         Count = Count \ 1000
   
         ' Pull out Days
         Days = Count \ (24& * 3600&)
         If Days > 0 Then Count = Count - (24& * 3600& * Days)
   
         ' Pull out HH:MM:SS
         Hours = Count \ 3600&
         If Hours > 0 Then Count = Count - (3600& * Hours)
         Minutes = Count \ 60
         Seconds = Count Mod 60
   
         ' Create a Message with info in it
         Message = Days & " Day(s), " & Hours & " Hour(s), " & Minutes
         Message = Message & " Minute(s), " & Seconds
         Message = Message & " Second(s) Since Windows Started!"
   
         ' Display Message in a Message Box
         MsgBox Message
      End Sub
   
   

5. Start the program (or press the F5 key).

6. Click the Command1 button. The message box should display the amount of time that has elapsed since Windows was started.

REFERENCES

For more information, see the Microsoft Windows SDK, Programmer's Reference (Book 2), Functions.