Daylight Savings Time

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dwvanguard

Member
Joined
Sep 9, 2013
Messages
11
I've had to set my clock to "Alaska" time zone in order to get the correct time ever since the time change.
Not a big deal, but :roll:

I should be on Pacific time zone with Daylight Savings turned "on," right?
I tried turning DLS on and off, but it was wrong (and the same) either way. Same time an hour off. The time never adjusted on its own.

What gives?
 
I had a similar problem occurred with my RAV4 EV. When Pacific Standard Time took place on November 4th, when clocks rolled back one hour, the clock in my RAV4 EV did not change. I didn't see any way to adjust it. I ended-up turning off the Daylight Savings Time option and it rolled back one hour. Not sure why it didn't change automatically.
 
I have yet to have any of my Navigation based cars get it correct - I have always had to do some intervention, whether if it is turn DST on/off or just by forcing the hour forward or back. They have all required some intervention.

I figure it as normal... My watches all need setting... I am just happy my phones and computers don't.

I really wish they would just dump the entire time change. My parents live in Arizona where they don't change, and it is so much nicer.

I hate having to deal with it, I deal with people all over the world, and it always causes issues figuring out time zones.
 
yes i just turned DST off.

The navigation system can obtain extremely accurate time from the GPS receiver, however I believe that unlike HF radio WWVB signals the GPS signal does not contain an indicator that Daylight Time (aka "Summer Time" in other parts of the world) is in use in the United States. It's expected that any GPS-clock base device would have this problem, there's actually nothing Toyota could do about it without including additional hardware.

So your GPS based devices can't actually auto-set themselves for DST "correctly" especially after the next time Congress decides to change the observance of Daylight Time. This is (at least) true of the Seiko GPS watches as well. (You could build in the "current" definition of DST but there's no guarantee it wouldnt change next year).

The HF Radio based WWVB signal broadcast from Fort Collins, Colorado, has always included this indicator, so a lot of non-GPS based "auto-setting" clocks will select the correct time automatically even if the observance changes in the future.

Summer Time is a big pain in the butt to people who design computer systems, countries change their observance of it a good # of times per year (across all countries) including most recently Libya, which cancelled returning to Standard Time a few hours before it was supposed to occur this year. (why? who knows. But governments get to do this.)
 
dwvanguard said:
I've had to set my clock to "Alaska" time zone in order to get the correct time ever since the time change.
Not a big deal, but :roll:

I should be on Pacific time zone with Daylight Savings turned "on," right?
I tried turning DLS on and off, but it was wrong (and the same) either way. Same time an hour off. The time never adjusted on its own.

What gives?

As I understand it, "normal time" (as opposed to "Daylight Savings Time") is based on a reference point the whole world agreed to. Daylight Savings Time is basically only a "local" (ie. the US) time change: 1hr ahead, so you turn it "ON" in the Spring and turn it "OFF" in the fall. So the "ON" / "OFF" in our nav control is to turn on/off DST, not turning on/off the automatic time change for DST. I guess the same Nav system could be sold elsewhere in the world where there's no DST, and they would never turn it "ON" there.


tjka4231 said:
I had a similar problem occurred with my RAV4 EV. When Pacific Standard Time took place on November 4th, when clocks rolled back one hour, the clock in my RAV4 EV did not change. I didn't see any way to adjust it. I ended-up turning off the Daylight Savings Time option and it rolled back one hour. Not sure why it didn't change automatically.

This is the correct way to do it. Now that we are in "normal" time, we should turn "OFF" DST in our nav system, and set the clock appropriately. Come Spring, we turn "ON" DST in our nav system, and the clock should adjust forward one hour.
 
occ said:
As I understand it, "normal time" (as opposed to "Daylight Savings Time") is based on a reference point the whole world agreed to. Daylight Savings Time is basically only a "local" (ie. the US) time change: 1hr ahead, so you turn it "ON" in the Spring and turn it "OFF" in the fall. So the "ON" / "OFF" in our nav control is to turn on/off DST, not turning on/off the automatic time change for DST. I guess the same Nav system could be sold elsewhere in the world where there's no DST, and they would never turn it "ON" there.

There are plenty of places in the USA that don't have DST, like the entire state of Arizona. Plus, much of Europe observes DST.
 
TonyWilliams said:
There are plenty of places in the USA that don't have DST, like the entire state of Arizona. Plus, much of Europe observes DST.

The problem is that Summer Time is observed between different dates in different countries (and often in the same country in different years). The United States has changed it 4 times in my lifetime for instance.

*Much* more detail here https://en.wikipedia.org/wiki/History_of_time_in_the_United_States
 
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