wscript.echo lst & Chr(10)& Chr(13) & "Calculated from your system clock." & Chr(10)& Chr(13) & "Accounting for US Daylight Saving Time." & Chr(10)& Chr(13) & "For longitude " & getlongitude

'====================================================================
'============================CALC LST================================

Function LST()

   Dim sidtime

   jd0 = calcJD()

   sidtime = calcST(jd0)

   LST = sidtime

end function	

Function LSTdms()

   Dim sidtime

   jd0 = calcJD()

   sidtime = calcST(jd0)

   LST = sidtime

end function	


Function getLongitude
   'Set your longitude here
   getLongitude=-117.7133333333
End Function

Function getTime(thetime)
   Dim thehour, theminute, thesecond
   thehour = Hour(thetime)
   theminute = Minute(thetime)
   thesecond = Second(thetime)
   getTime = thehour + theminute/60 + thesecond/3600
end Function

Function getTzone()
   dim longit
   longit = getLongitude()
   getTzone = CInt(longit/15) + CheckDaylightSavingTime()
End Function

Function calcJD()
'creates t and jdy0

   dim y, m, d, t, tzone
   y = Year(Now)
   m = Month(now)
   d = Day(now)
   t = getTime(now)
   tzone = getTzone()

   if m <= 2 then
	y = y - 1
	m = m + 12
   end if
	
   Dim a, b, jdg, jdyo
      jdyo = 0
   a = Int(y/100)
   b = 2 - a + Int(a/4)
   d = d + t/24
   jdg = Int(365.25*(y+4716))+Int(30.6001*(m+1))+d+b-1524.5

   ' Correct the time for UT from local standard time - this only sets up calc to give the right jd for 0h UT
   jdg = jdg - tzone/24

   jdyo = Int(jdg+0.5) - 0.5 ' Julian day 0h UT
   calcJD = jdyo

end Function


Function calcST(jdi)  

   Dim t1,t2,tzone2
      t = getTime(now)
      t1 = 0
      tzone = getTzone()
   Dim longitude
      longitude = getLongitude()

   Dim st, ut, n
   Dim hr, mn, sc

   ' calculate the siderial time at Greenwich in degrees at 0h UT
   t1 = (jdi-2451545.0)/36525
   st = 100.46061837+36000.77053608*t1+0.000387933*t1*t1-t1*t1*t1/38710000  

   ' correct for other time and time zone 
   ' remember that julian day is for 0h UT (add in time plus time zone (negative =west))  
   ' The following gives the UT for the time, t in time zone tzone
   ut = (t-tzone)

   ' example if tzone = -4 hours and time = 15 hours (3 pm) then UT = 15+4 = 19 hours (remember st is in degrees)
   st = st + 1.002738*ut*15 

   ' Now calculate local siderial time which is your longitude less than the st at greenwich
   st = st+longitude

   ' Reduce the angle to 0-360
   if st < 0 then
      n = Int(Abs(st/360))
      st = st + ((n+1)*360)
   end if

   hr = Int(st/15)
   mn = Int(((st/15)-hr)*60)
   sc = CInt((((st/15)-hr)*60-mn)*60)
   if hr > 24 then
      n = Int(hr/24) 
      hr = hr - n*24
   end if
   siderial = ""&hr&"h"&mn&"m"&sc&"s"

   Dim LSTdec
   LSTdec = (st/15)
   if LSTdec > 24 then
      n = Int(LSTdec/24) 
      LSTdec = LSTdec - n*24
   end if

   calcST = LSTdec

end function

'^=^=^=^=^=^=^=^=^=^=^=^=^=^=CALC LST=^=^=^=^=^=^=^=^=^=^=^=^=^=^=^=^
'====================================================================

'------------------------DAYLIGHT SAVING TIME-----------------------

Function CheckDaylightSavingTime()

   dim theyear,themonth,theday,spring,fall
   theyear = year(Now)
   themonth = month(Now)
   theday = day(Now)
   
   spring = SpringAhead(theyear)
   fall = FallBack(theyear)
   
   If themonth >= 1 Then
      If themonth < 4 Then
         CheckDaylightSavingTime = 0
      end if
   end if
   if themonth = 4 Then
      if theday >= spring Then
         CheckDaylightSavingTime = 1
        Elseif theday < spring Then
         CheckDaylightSavingTime = 0
      end if
   end if
   if themonth > 4 Then
      if themonth < 10 Then
         CheckDaylightSavingTime = 1
      end if
   end if
   if themonth = 10 Then
      if theday < fall Then
         CheckDaylightSavingTime = 1
        Elseif theday >= fall then
         CheckDaylightSavingTime = 0
      end if
   end if
   if themonth > 10 Then
      if themonth <= 12 Then
         CheckDaylightSavingTime = 0
      end if
   end if

End Function

Function SpringAhead(yeary) 
   Dim thisYear, AprilDate, ADshort
   thisYear = CInt(yeary)
   ADshort = 2+6*thisYear-Int(thisYear/4)
   AprilDate = CInt(( ADshort/7 - Int(ADshort/7) )*7 + 1)
   SpringAhead = AprilDate
End Function

Function FallBack(yeary)
   Dim thisYear, OctoberDate, ODshort
   thisYear = CInt(yeary)
   ODshort = Int(thisYear*5/4)+1
   OctoberDate =  CInt(31-( ODshort/7 - Int(ODshort/7) )*7)
   FallBack = OctoberDate
End Function

'---------------------------------------------------------------------