Android Question StartServiceAt UTC or Local Ticks

[canalrun]

I am going to be using StartServiceAt() to run a service at dawn then again at dusk. There is a web site with a JSON interface that gives me the dawn/dusk times as text strings in UTC.

I would like to use these times with StartServiceAt().

Do I need to convert the text strings to local time before I convert them to ticks in order to pass as the time parameter? Or should I leave them in UTC format (I am in time zone UTC -5)?

Thanks,
Barry.

 

[Erel]

Tip: ticks = number of milliseconds since 1/1/1970 00:00 UTC

The best way is to parse the time string with explicit time zone (UTC in this case). Can you give an example of the date string you receive from the server?

 

[canalrun]

Thanks. As I was searching the forum I came upon another post where you suggested setting the DateTime.SetTimeZone(0) before converting the time string to ticks using the DateTime.TimeParse function.

For example, the string I get will look like "11:13:00 AM". This is in UTC. It should correspond to 6:13:00 AM for sunrise at my location (I'm UTC -5).

I believe I should do the following:

DateTime.SetTimeZone(0)
DateTime.TimeFormat = "hh:mm:ss a"
Dim ticks0 As Long = DateTime.TimeParse("11:13:00 AM") ' format of example time returned from JSON get sunrise HTTP

Then restore my default time zone and parse format.
Use the ticks0 value I got in my StartServiceAt call.

I'm hoping this should start the service at 6:13 AM my time so I can turn off my bulb.

Barry.

 

[Erel]

Another option:

Sub ParseUTCTime (time As String) As Long
    Dim m As Matcher = Regex.Matcher("(\d+):(\d+):(\d+)\s(\w+)", time)
    If m.Find = False Then Return 0
    Dim hours As Int = m.Group(1) Mod 12
    Dim minutes As Int = m.Group(2)
    Dim seconds As Int = m.Group(3)
    Dim am As Boolean = m.Group(4).ToLowerCase = "am"
    If am = False Then hours = hours + 12
    Return DateUtils.SetDateAndTime2(DateTime.GetYear(DateTime.Now), DateTime.GetMonth(DateTime.Now), DateTime.GetDayOfMonth(DateTime.Now), _
        hours, minutes, seconds, 0)
End Sub