Calculation for sunrise and sunset time

         Protected Function calculate(input_date As DateTime, set_rise As Integer, offset As Double)
         'Convert longitude into hour value
         Dim long_hour As Double = longitude / 15
         Dim t As Double

        'sunset = 0, sunrise = 1
        'calculate approximate time
        If (set_rise = 1) Then
            t = input_date.DayOfYear + ((6 - long_hour) / 24)
        ElseIf (set_rise = 0) Then
            t = input_date.DayOfYear + ((18 - long_hour) / 24)
        End If

        'Calculate Sun's mean anomaly time
        Dim mean As Double = (0.9856 * t) - 3.289

        'Calculate Sun's true longitude
        Dim sun_true_long As Double = mean + (1.916 * Math.Sin(mean * D2R)) + (0.02 * Math.Sin(2 * mean * D2R)) + 282.634
        If (sun_true_long > 360) Then
            sun_true_long = sun_true_long - 360
        ElseIf (sun_true_long  360) Then
            right_ascension = right_ascension - 360
        ElseIf (right_ascension  1) Then
            Response.Write("Sun never rises on this day. " & input_date.Year & "/" & input_date.Month & "/" & input_date.Day & "
")
        ElseIf (cosH < -1) Then
            Response.Write("Sun never sets on this day. " & input_date.Year & "/" & input_date.Month & "/" & input_date.Day & "
")
        End If

        'Calculate and convert into hour of sunset or sunrise
        Dim hour As Double = 0
        If (set_rise = 1) Then
            hour = 360 - R2D * Math.Acos(cosH)
        ElseIf (set_rise = 0) Then
            hour = R2D * Math.Acos(cosH)
        End If

        hour = hour / 15

        'Calculate local mean time of rising or setting
        Dim local_mean_time As Double = hour + right_ascension - (0.06571 * t) - 6.622

        'Adjust time to UTC
        Dim utc As Double = local_mean_time - long_hour

        'Convert time from UTC to local time zone
        Dim local_time As Double = utc + offset
        If (local_time > 24) Then
            local_time = local_time - 24
        ElseIf (local_time < 0) Then
            local_time = local_time + 24
        End If

        'Convert the local_time into time format
        Dim s_hour As Integer = Math.Floor(local_time)
        Dim s_minute As Integer = Math.Floor((local_time - s_hour) * 60)

        If (s_minute < 10) Then
            Return s_hour & ":0" & s_minute
        Else
            Return s_hour & ":" & s_minute
        End If

    End Function
 

Retrieving data

  Protected Function Get_Data(ByVal query As String)
    Dim result As String
    result = ""
    'Database connection string. Replace lower capital with MySQL database settings
    Using Con As New MySqlConnection("Database=database;Server=server;User ID=userid;Password=password;ignore prepare=false")
    Con.Open()
    Using Com As New MySqlCommand(query, Con)
    Com.CommandType = Data.CommandType.Text
    Using RDR = Com.ExecuteReader()
       If RDR.HasRows Then
          RDR.Read()
          result = RDR.Item("time_zone").ToString() & "," & RDR.Item("country_code") & "," & RDR.Item("latitude") & "," & RDR.Item("longitude")
        End If
     End Using
     End Using
     End Using
     Return result
 End Function

Converting IP address to IP number

Protected Function ip_to_number(ByVal ip_addr As String)
  Dim ip_block() As String
  Dim ip_num As Long

  ip_block = Split(ip_addr, ".")
  ip_num = (ip_block(0) * (256 ^ 3)) + (ip_block(1) * (256 ^ 2)) + (ip_block(2) * 256) + ip_block(3)

  Return ip_num
End Function