GetTimeZoneInformation api can be used to fetch the timezoen of a user's computer.
Example
{code}
Private Const TIME_ZONE_ID_STANDARD = 1
Private Const TIME_ZONE_ID_UNKNOWN = 0
Private Const TIME_ZONE_ID_INVALID = &HFFFFFFFF
Private Const TIME_ZONE_ID_DAYLIGHT = 2
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
Type TIME_ZONE_INFORMATION
Bias As Long
StandardName(62) As Byte
StandardDate As SYSTEMTIME
StandardBias As Long
DaylightName(62) As Byte
DaylightDate As SYSTEMTIME
DaylightBias As Long
End Type
Declare Function GetTimeZoneInformation Lib "kernel32" _
(lpZoneInfo As TIME_ZONE_INFORMATION) As Long
Public Function GetTZ() As String
Dim pZoneInfo As TIME_ZONE_INFORMATION
Dim nRetVal As Long
Dim sDayLight As String
nRetVal = GetTimeZoneInformation(pZoneInfo)
n = CStr(pZoneInfo.StandardName)
If InStr(1, n, "India Standard Time", vbTextCompare) Then
f = "IST"
ElseIf InStr(1, n, "Eastern Standard Time", vbTextCompare) Then
If nRetVal = TIME_ZONE_ID_DAYLIGHT Then
f = "EDT"
Else
f = "EST"
End If
End If
GetTZ = f
End Function
{/code}
In the example, the GetTZ() returns IST for Indian standard time and EDT for Eastern time with daylight savings and EST for Eastern standard time.