The following script (in VBScript) will set the date and time on the local PC clock to 13:13 on 10/10/09:
Dim
WshShell
Set WshShell = CreateObject("WScript.Shell")
WshShell.Visible = false
WshShell.Run "cmd /C time 13:13"
WshShell.Run "cmd /C date 10/10/09"
Set WshShell = Nothing