Manual time.

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esilvester

New member
Joined
Nov 8, 2019
Messages
4
There is a UTC time signal in the RDS payload in FM transmission.
There is UTC time signal in DAB radio broadcasts.
There is UTC time signal in the 2/3/4G sim connectivity
There is UTC time signal in GPS signal used in navigation
There is UTC time signal online in the connected services.

So why does BMW make you enter the time manually???! And then change it for summertime or as you drive over a timezone, even though it knows where you are? :shock:
 
Do you have auto set time selected?

I do, and have observed some clock inaccuracies that required manual intervention (deselecting / reselecting auto time set), but nothing that required manual adjustment.

I was happy to find the car self-adjusted to standard time automatically.
 
No I don't - which rather wipes out my post. Maybe I should have posted a more humble "How do I set auto time?"

(BTW, how do I set auto time? )
 
Settings > Time and Date > Auto Time Settings (click to toggle on/off)
 
Note that I discovered that auto time (GPS time) did NOT set my clock back when DST ended a few weeks ago. I thought that pre-condition didn't run, until I noticed half way to work that the clock didn't fall back an hour..... :roll:
 
Oh, odd. What model year is yours?

I don't know how our vehicles know when to make the adjustment, short of having a table loaded with the changeover date loaded as a rule. It's not broadcast by GPS satellites -- those only broadcast UTC. What happens if the car is in Arizona or Hawaii?

I have a simple clock radio at home that has an automatic DST changeover, but it was manufactured prior to the most recent (2005) change of the DST dates. So it's automatically wrong for a few weeks twice per year. I'm sure it's programmed with a simple rule to follow. I'd bet it would make the change if it were plugged in in Arizona.

For what it's worth, my 2013 Audi and 2016 Volvo both make the change automatically, but my 2013 Ford (which also features auto time-set) requires manual DST adjustments.
 
I don't know how our vehicles know when to make the adjustment, short of having a table loaded with the changeover date loaded as a rule. It's not broadcast by GPS satellites -- those only broadcast UTC. What happens if the car is in Arizona or Hawaii?

The car has cell service - and 'should' update the time, according to the time of the local cell service/towers, just like your cell phone does. However, though mine is set for auto update, I had to manually adjust the time for daylight savings, as it did not change automatically.
 
MKH said:
The car has cell service - and 'should' update the time, according to the time of the local cell service/towers, just like your cell phone does. However, though mine is set for auto update, I had to manually adjust the time for daylight savings, as it did not change automatically.

I have hardware Stratum 1 NTP time servers at both work and home, because I'm anal about the time. After a week of ownership of my new-to-me late 2015 model last spring, the clock was consistently 2 minutes fast even though it was set for auto time sync. I don't know which carrier(s) BMW uses for their telematics service, so I have no idea if this is because the carrier's clock is fast or because of a problem in the car's sync function.

During the summer, I was tinkering with some coding options and enabled GPS time sync while I was in there. Obviously, an unknown side effect of using that setting is that DST updates apparently will never happen. I'm actually now wondering if the GPS time sync coding even does anything, since I never verified the seconds accuracy and set the clock back manually by the manual time setting and not a timezone/DST offset setting.....
 
So according to this old thread, some i3 models have it activated, and others need to be enabled in coding:

https://www.mybmwi3.com/forum/viewtopic.php?t=3832

...and if THAT is accurate, the coding option suggests the time signal is pulled from GPS, not cell.

If the GPS time code is 2 minutes off, it's the end of days. :(

I've experienced the same 2 minute time error. I had to uncheck and recheck Auto Time Set to get the clock right. It seems to be keeping good time since then, but I haven't checked down to the second.
 
To get the current TOD from gps, the user needs to know how many leap seconds to apply as the time code does not account for those over the years...it just keeps counting, the receiver needs to adjust. But, there have only been 37 since the advent of the gps system, so if you are using that signal and not correcting for those leap seconds, you'd be off 37-seconds from the current recognized time of day.
 
I realize we're getting into the weeds here, but any modern GPS receiver found built-in to a vehicle will read the almanac data that is transmitted as part of the GPS data stream -- data that includes the number of leap seconds as well as upcoming ones -- and will automatically apply that correction to GPS time in order to present an accurate UTC.
 
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