Attribute VB_Name = "unixtime"
Option Explicit

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' Copyright ©1996-2011 VBnet/Randy Birch, All Rights Reserved.
' Some pages may also contain other copyrights by the author.
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' Distribution: You can freely use this code in your own
'               applications, but you may not reproduce
'               or publish this code on any web site,
'               online service, or distribute as source
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Private Const TIME_ZONE_ID_UNKNOWN As Long = 1
Private Const TIME_ZONE_ID_STANDARD As Long = 1
Private Const TIME_ZONE_ID_DAYLIGHT As Long = 2
Private Const TIME_ZONE_ID_INVALID As Long = &HFFFFFFFF

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 Type TIME_ZONE_INFORMATION
   Bias As Long
   StandardName(0 To 63) As Byte  'unicode (0-based)
   StandardDate As SYSTEMTIME
   StandardBias As Long
   DaylightName(0 To 63) As Byte  'unicode (0-based)
   DaylightDate As SYSTEMTIME
   DaylightBias As Long
End Type

Private Declare Function GetTimeZoneInformation Lib "kernel32" _
    (lpTimeZoneInformation As TIME_ZONE_INFORMATION) As Long

Function GetCurrentGMTfrom1970() As Long

   Dim tzi As TIME_ZONE_INFORMATION
   Dim gmt As Date
   Dim dwBias As Long

   Select Case GetTimeZoneInformation(tzi)
   Case TIME_ZONE_ID_DAYLIGHT
      dwBias = tzi.Bias + tzi.DaylightBias
   Case Else
      dwBias = tzi.Bias + tzi.StandardBias
   End Select

   gmt = DateAdd("n", dwBias, Now)
     
   GetCurrentGMTfrom1970 = DateDiff("s", "01/1/1970 12:00:00 AM", gmt)
End Function