Dashboard Clock versus Navigation Clock

I just bought a new Tacoma. The timezone and daylight savings time sets automatically from the GPS. On the Prime, not. Weird.

 

Clocks will all have to change again in a few weeks.

 

we just went thru a time change last weekend, and the nav time is now off an hour...

ok, this worked, just selected daylight savings along with gps auto and it is now correct... interesting that gps auto would not get it right by itself... but whatever works...

 

GPS time is oblivious to time zones and even leap seconds, although, as per wikipedia, "... satellite broadcasts include the necessary information to convert GPS time to UTC." And, of course, DST is a political decision anyway... and a pretty fine-grained database would need to be maintained worldwide.

 

Yeah well my Tacoma adjusts automatically for DST, so why not the Prime?

 

It sounds like you just need to tell the system that your area uses Daylight Savings Time. Not all areas in a timezone use it.
The Prime is not (yet) omniscient.

 

To put it as simply as possible, GPS satellites essentially broadcast only two pieces of information; the satellite's current location in space and the current UTC time when the transmission was sent. Yes to get into the techie stuff it actually broadcasts current GPS time plus UTC conversion factor, but that's essential saying the same thing.

At its most basic, all that the GPS receivers do that are built into our phones, our cars, etc. is receive the broadcast signal from four different satellites, and based on the time difference between the four signals calculate the latitude and longitude of the receiver. In fact many early portable GPS devices used by hikers only displayed latitude and longitude on a small LCD display, the hiker then used this information to find their location on a USGS map.

A modern GPS receiver however also contains a map database, on which it displays the receiver's current position. Or if using Google Maps on a phone it uses an online map database. The GPS receiver's database can (or at least should) contain internal time zone maps as well as information about DST such as the dates for switching and rules for different states/countries. A GPS receiver that cannot automatically adjust for time zone or daylight savings time is pretty weak in my opinion.

 

As you stated, Toyota could indeed maintain such a database and all you said falls within the realm of the technically possible. However, what happens if/when our Indiana friends (no sarcasm intended) decide to switch a county to another time zone and/or on/off DST? Now you get stuck with an obsolete database until you pay (dearly) for a Toyota update.

Just curious now: given that in Europe the regulations concerning time zones and DST are much more rigid, does the Primes sold there automatically adjust for DST?

 

But only people who live in or drive through those counties would be affected. And actually systems that I have used that have auto DST, you also have the option to manually adjust DST, so the people in those counties wouldn't have to buy a new database if they don't want to, they could manually adjust for DST twice a year, something that currently everyone in the country has to do who owns a Prime even with a current database.

 

You're probably right and I'm being overly picky. And as @MikeDee stated, other Toyotas do have this functionality...

 

I don't think you are being overly picky, it is a problem, but it's one that has affected pretty much all nav systems with built in databases. The answer I think is either free updates like most of the portable GPS units now have, or an online database, which is actually a huge benefit not just for time zones but for everything else. That's one of the huge benefits of Google Maps, so much so that I use it almost exclusively now instead of my Garmin even though I like the Garmin interface better, because it's so important to have up to date data. I hate when I'm traveling and I search for a store or restaurant on my Garmin and drive all the way to it and find out it's no longer there, meanwhile there was probably a new one closer to where I already was. I never have that problem with Google Maps. The only draw back to Google Maps is it doesn't work very well when you lose Internet connection. It allows you to store the current map on your phone, but you have to do that proactively. I wish it would automatically store whatever area I am currently driving, of course it would need a way to set a storage limit, otherwise if you were on a long trip across several states you might fill up your phone's storage.