date and GPS related questions

Daniel Willmann daniel at
Sun Mar 15 15:47:04 CET 2009

On Sun, 15 Mar 2009 14:41:03 +0100
Fernando Martins <fernando at> wrote:

> Daniel Willmann wrote:
> > Timezone will be set according to the nationality of the GSM network
> > you're associated to. Since this is annoying for a couple of people
> > we'll probably make this optional/prompt for new timezone.
> >
> > Time will be updated either through NTP if your FR has a connection
> > to the Internet or through GPS if you wait long enough.
> >   
> I'm a bit confused with this: I would assume that if timezone is 
> changed, time/date would be automatically updated. So, why then

There are a couple reasons actually.
First, determining timezone based on the country code of the GSM
network you're logged in does not give you any indication of the actual
Second, the actual timezone and time cellbroadcast messages are not
sent by all providers. In Germany none of the providers support these...
Third, even if time is sent as cellbroadcast the time sent can be off
by a couple of minutes (warning, this is hearsay. I have no real
experience with time cellbroadcast messages).

> bother to update time based on NTP or GPS? Also, it would be nice to
> know, grossly, how much is "long enough", but I suppose it's not yet
> done or decided...

IIRC otimed (Jan should know better) will listen to the time signal of
the GPS (which is only sent if GPS is on) and adjust the system time
accordingly. Same with ntp which is checked periodically (and only
works if a network connection is present, obviously).

> periods, usually I do. I think it would be nice to go to a date/time
> setting panel having (also) a  button to just change the timezone. Of
> course this requires the FR to know at all times that the set
> timezone is not the local one.

I'm not sure I understand completely. I can't see why one wouldn't want
to set the proper time (maybe with an offset option for people
notoriously being late so they can set the clock to <real-time> + 5min).

Could you explain some more what you mean by that?
You can already statically enable specific time(-zone) sources or
disable them all together in /etc/frameworkd.conf:
# a list of time/zone sources to use or NONE
timesources = GPS,NTP
zonesources = GSM

> Also, a very small but annoying issue: busybox date command displays
> a very brief help string that does not tell which is the input format
> to set date/time. If one is on the road, without a GUI to set
> date/time, and no man page, the format is difficult to guess (date -s 
> I suggest to show this format on the help string of 
> date (I know technically it is a trivial change, but no idea of what 
> this involves regarding patch bureaucracy).

Yes, I have learned to have busybox for this and similar reasons. Maybe
some day we'll replace it with the real packages, but I don't know how
much space that will eat.
Anyway, what I would want on the road (regardless of the busybox
annoyance, which should be fixed) is actually a GUI to change date/time.

Daniel Willmann
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