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Convert time to UTC vbScript

I have the following function that works great when converting current time to UTC.

Function toUtc(byVal dDate)
    Dim oShell : Set oShell = CreateObject("WScript.Shell")
    toUtc = dateadd("n", oShell.RegRead("HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\TimeZoneInformation\ActiveTimeBias"), cDate(dDate))
End Function

However, I think that this inadequately handles the conversion of future or historical dates to UTC, since the function should know the time zone offset of the server at the time of the convertible date, and also whether it was not in the summer or not.

How can I get around this?

I am using vbScript / Classic ASP on a windows server with IIS7.5

To clarify, this has nothing to do with date formatting. It's all about converting to UTC from the server time zone for historical dates. In the summer, the offset will be disabled for 60 minutes if I try to convert the date and time to standard time.

For instance:

, , 2013-02-19 ( ), , , 2008-06-05 ( ) PDT ( ) UTC. , 60 ( PST ( PDT), ).

, UTC-7 UTC-8 , DST . UTC , , DST .

+6
4

, @AardVark71.

func.asp:

<script language="javascript" runat="server">
    function toUtcString(d) {
        var dDate = new Date(d);
        return Math.round(dDate.getTime() / 1000);
    };
</script>

. asp- :

response.Write DateAdd("s", toUtcString(cDate("11/11/2012 06:25 PM")), "01/01/1970 00:00:00") 'expect 11/11/2012 10:25:00 PM gmt/utc time
response.Write DateAdd("s", toUtcString(cDate("06/11/2012 06:25 PM")), "01/01/1970 00:00:00") 'expect  6/11/2012  9:25:00 PM gmt/utc time

( ) , DST.

+4

ASP classic VBScript JScript . JScript Date UTC. :

<%@ language="vbscript" %>
<%
Option Explicit
Dim local_date
Dim utc_date
For Each local_date In Array("11/11/2012 06:25 PM", "06/11/2012 06:25 PM")
    utc_date = local_to_utc(local_date)
    Response.Write "Local: " & local_date & ", UTC: " & utc_date & vbNewLine
Next
For Each utc_date In Array("2012-11-12T02:25:00Z", "2012-06-12T01:25:00+00:00")
    local_date = utc_to_local(utc_date)
    Response.Write "UTC: " & utc_date & ", Local: " & local_date & vbNewLine
Next
%>
<script language="jscript" runat="server">
    function local_to_utc(datestr) {
        // note that this function lets JScript engine parse the date, correctly or otherwise
        var date = new Date(datestr);
        var result = date.getUTCFullYear() + "-" + (date.getUTCMonth() + 1) + "-" + date.getUTCDate() + "T" + date.getUTCHours() + ":" + date.getUTCMinutes() + ":" + date.getUTCSeconds();
        return result.replace(/(\D)(\d)(?!\d)/g, "$10$2") + "Z";
    }
    function utc_to_local(datestr) {
        // note that this function parses only a subset of ISO 8601 date format
        var match = datestr.match(/^(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2}):(\d{2})(?:\.(\d{3}))?(?:Z|([-+])(\d{2}):(\d{2}))$/);
        var offset = match[8] ? (match[8] === "+" ? 1 : -1) * (match[9] * 60 + match[10] * 1) : 0;
        var date = new Date(Date.UTC(match[1], match[2] - 1, match[3], match[4], match[5] - offset, match[6], match[7] || 0));
        var result = date.getFullYear() + "-" + (date.getMonth() + 1) + "-" + date.getDate() + " " + date.getHours() + ":" + date.getMinutes() + ":" + date.getSeconds();
        return result.replace(/(\D)(\d)(?!\d)/g, "$10$2");
    }
</script>

:

PST/PDT:

Local: 11/11/2012 06:25 PM,       UTC:   2012-11-12T02:25:00Z
Local: 06/11/2012 06:25 PM,       UTC:   2012-06-12T01:25:00Z
UTC:   2012-11-12T02:25:00Z,      Local: 2012-11-11 18:25:00
UTC:   2012-06-12T01:25:00+00:00, Local: 2012-06-11 18:25:00
+1

-, , ?

WMI Win32_TimeZone Bias. MSDN: " UTC Time", :

Win32_ComputerSystem CurrentTimeZone, Win32_TimeZone Bias .

, , .

' "." mean local computer
WScript.Echo FormatDateTime(UTCDate("."), 0)

Function UTCDate(strComputer)
    Dim objWMIService, ColDate, ColCS

    On Error Resume Next
    Set objWMIService = _
        GetObject("winmgmts:{impersonationLevel=impersonate}!\\" _
        & strComputer & "\root\cimv2")

    Set ColDate = objWMIService.ExecQuery("Select * From Win32_LocalTime")

    UTCDate = DateSerial(100, 1, 1)
    For Each objDate In ColDate
        UTCDate = DateAdd("yyyy", ObjDate.Year - 100, UTCDate)
        UTCDate = DateAdd("m", ObjDate.Month - 1, UTCDate)
        UTCDate = DateAdd("d", ObjDate.Day - 1, UTCDate)
        UTCDate = DateAdd("h", ObjDate.Hour, UTCDate)
        UTCDate = DateAdd("n", ObjDate.Minute, UTCDate)
        UTCDate = DateAdd("s", ObjDate.Second, UTCDate)
    Next

    ' http://msdn.microsoft.com/en-us/library/windows/desktop/ms696015(v=vs.85).aspx
    Set ColCS = objWMIService.ExecQuery("Select * From Win32_ComputerSystem")

    Dim TimeZoneOffset, LocalTimeZone
    For Each LocalTimeZone In ColCS
        TimeZoneOffset = LocalTimeZone.CurrentTimeZone
    Next

    If TimeZoneOffset < 0 Then
        TimeZoneOffset = Abs(TimeZoneOffset)
    Else
        TimeZoneOffset = -Abs(TimeZoneOffset)
    End If

    UTCDate = DateAdd("n", TimeZoneOffset, UTCDate)
    If Err Then UTCDate = vbNull
    Set objWMIService = Nothing
End Function

[EDIT] , , MSDN (, , ). , , , . , -.

P.S. , "".

, (), PDT . PDT. , . , .

With New DateDrill
    Debug.WriteLine .UTCDate("2008-6-28")
    Debug.WriteLine .UTCDate("2014-1-21")
End With

Class DateDrill

    Public Function UTCDate(ByVal dtDate)
        If Not IsDate(dtDate) Then Err.Raise 5
        dtDate = CDate(dtDate)
        Dim ZoneBias: ZoneBias = TimeZoneBias()
        If IsPDT(Now) <> IsPDT(dtDate) Then
            ZoneBias = ZoneBias - 60
        End If
        UTCDate = DateAdd("n", ZoneBias, dtDate)
    End Function

    Private Function IsPDT(ByVal dtDate)
        If Not IsDate(dtDate) Then Err.Raise 5
        dtDate = CDate(dtDate)
        Dim pdtLow, pdtUpr, nDaysBack

        pdtLow = DateSerial(Year(dtDate),  3, 31)
        pdtUpr = DateSerial(Year(dtDate), 10, 31)
        pdtLow = DateAdd("h", 2, pdtLow)
        pdtUpr = DateAdd("h", 2, pdtUpr)

        nDaysBack = Weekday(pdtLow) - 1
        If nDaysBack <> 0 Then
            pdtLow = DateAdd("d", -nDaysBack, pdtLow)
        End If

        nDaysBack = Weekday(pdtUpr) - 1
        If nDaysBack <> 0 Then
            pdtUpr = DateAdd("d", -nDaysBack, pdtUpr)
        End If

        IsPDT = (dtDate >= pdtLow And dtDate <= pdtUpr)
    End Function

    Private Function TimeZoneBias()
        Dim LTZone
        With GetObject("winmgmts:" & _
                "{impersonationLevel=impersonate}!\\.\root\cimv2")
            For Each LTZone In .ExecQuery(_
                    "Select * From Win32_ComputerSystem")
                TimeZoneBias = LTZone.CurrentTimeZone
            Next
        End With
        TimeZoneBias = TimeZoneBias * -1
    End Function

End Class
0

ASP VBScript , . Unix MySQL. , Unix. .

Note: pquery- This is my own function for executing SQL queries. Obviously replace in your own method.

I calculate the offset every time it starts unixTime(). Of course, you can calculate it once in the boot file and set a global variable if you want.

Function unixTimestamp()
    ' Unix Timestamp, drawn from MySQL because ASP does not natively handle time zones
    rs = pquery( "SELECT unix_timestamp() AS 'ts'", null )
    unixTimestamp = cLng( rs("ts") )
End Function

Function utc_offset()
    ' Offset of Server time from UTC, in seconds
    dim unixNow : unixNow = unixTimestamp()
    dim aspNow  : aspNow  = cLng( DateDiff( "s", "01/01/1970 00:00:00", now() ) )
    utc_offset = cLng( ( aspNow - unixNow ))
End Function

Function unixTime( byVal dt )
    dim offset : offset = utc_offset()
    if( VarType( dt ) = vbDate ) then
        unixTime = cLng( DateDiff( "s", "01/01/1970 00:00:00", dt ) - offset )
    else
        if( isDate( dt ) ) then
            dt = cDate( dt )
            unixTime = cLng( DateDiff( "s", "01/01/1970 00:00:00", dt ) - offset )
        else
            unixTime = null
        end if
    end if
End Function

Function datetimeFromUnix( byVal udt, offset )
    datetimeFromUnix = cDate( DateAdd( "s", udt + offset , "01/01/1970 00:00:00" ) )
End Function

Now run:

utcTimestamp = unixTime( dDate )
utcDate = datetimeFromUnix( utcTimestamp, 0 )   ' UTC
localDate = datetimeFromUnix( utcTimestamp, utc_offset() )  ' back where we started
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