'_______________________________________________________________
'DAYLIGHT SAVING TIME TEST - Written By Warwick Black 28/10/2005
'warwick.black@citect.com
'
'SUMMARY: 
'This Function reads two registry settings, to determine
'whether the system clock is compensating for Daylight Saving Time.
'The code reads two registry entries, the 'ActveTimeBias' and the 
''Bias' from the TimeZoneInformation section.
'The 'Normal' time bias is the usual time variation from GMT, whereas the 
''ActiveTimeBias' is the variation actually being used. If they are not equal, 
'then the system clock is adding compensation for Daylight Saving Time.

'USAGE:
'Call from a Button using:

'Civba
'CheckDaylight

'Or by a timed event etc.
'_______________________________________________________________


Dim strFullPath 'Stores full registry key paths
Dim stDefault
Dim objReg
Dim objSubKey, arrSubKeys
Const strComputerName = "."

'This function enables the reading of registry entries
Public Function WMIGetSetting (stRoot, stSection, stKey, stAppPath)

	On Error Goto HANDLE_ERR
	strFullPath = stAppPath & "\" & stSection
	 
	Set objReg = GetObject("winmgmts:{impersonationLevel=impersonate}!\\" & strComputerName & "\root\default:StdRegProv")
	 
	objReg.GetdwordValue stRoot, strFullPath, stKey, stDefault
	WMIGetSetting = stDefault 'Get string value of key
Exit Function
	
	HANDLE_ERR:
	MsgBox Err.Description
End Function

'This the function that is called to determine whether Daylight Saving Time is active or not
Public Sub CheckDaylight()
	Dim ActiveTimeBias
	Dim Bias
	
	ActiveTimeBias = WMIGetSetting(&H80000002, "Timezoneinformation", "activetimebias","System\CurrentControlSet\Control")
	Bias = WMIGetSetting(&H80000002, "Timezoneinformation", "bias","System\CurrentControlSet\Control")
	
	If Bias <> ActiveTimeBias Then 	'DAYLIGHT SAVING TIME
		msgbox "Daylight Savings!!!"
		'ADD YOUR FLAG THAT YOU WISH TO SET/UNSET HERE
	
	Else							'NORMAL TIME
		msgbox "Normal Time"		
		'ADD YOUR FLAG THAT YOU WISH TO SET/UNSET HERE
	End If
	
End Sub