daylight saveings time
#21
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Originally Posted by das' date='Oct 31 2005, 10:53 AM
There are many reasons why a vehicle wouldn't adjust itself for daylight savings time.
First, cell phones can do it because they have a limited range from towers that are in a known time zone, and the provider already provides the time as it is.
Second, computers can do it because the default for any modern computer running Windows or Mac OS X is such that they synchronize your time with a network time server running the NTP protocol, and you have already specified which time zone your computer is in and whether or not you are in a locale with Daylight Savings Time. When the time changes, it gets updated via NTP.
I wouldn't say it's "easy" for a car to do it, or even for GPS to do it. GPS timekeeping is done with GMT/UTC time. It has no idea where your vehicle is. Now you might say, well, my *vehicle* knows where it is; after all, I have GPS! Yes. But then who maintains a profile for all geographic areas in the United States and provides that to the vehicle? NAVTEQ, perhaps? Ok, they could, and then provide an API for the automotive manufacturers to use the data, and BMW could then provide the ability to reset the clock for DST via iDrive. But then what happens when an energy bill gets passed that changes the DST switchover by about a month? How does your car find out about it? I've seen some people suggest an FM radio station. Sure, but then there would have to be a universally accepted standard for such a situation, and further, you're not guaranteed to be in the same time zone as a particular FM radio station under all circumstances. The bottom line is that it's not as easy as you think, and is *much* easier to have you, the user, change your offset from GMT twice a year. Other devices that reset their time do so because they can, easily. Your car can't. (Now, with a telematics service like BMW Online or BMW Assist/Teleservice, they could theoretically reset your clock as long as you maintained a profile with your timezone, or BMW built a service that used the GPS in your vehicle to determine your location for purposes of setting time. But this probably isn't a really high priority, as one would imagine.)
First, cell phones can do it because they have a limited range from towers that are in a known time zone, and the provider already provides the time as it is.
Second, computers can do it because the default for any modern computer running Windows or Mac OS X is such that they synchronize your time with a network time server running the NTP protocol, and you have already specified which time zone your computer is in and whether or not you are in a locale with Daylight Savings Time. When the time changes, it gets updated via NTP.
I wouldn't say it's "easy" for a car to do it, or even for GPS to do it. GPS timekeeping is done with GMT/UTC time. It has no idea where your vehicle is. Now you might say, well, my *vehicle* knows where it is; after all, I have GPS! Yes. But then who maintains a profile for all geographic areas in the United States and provides that to the vehicle? NAVTEQ, perhaps? Ok, they could, and then provide an API for the automotive manufacturers to use the data, and BMW could then provide the ability to reset the clock for DST via iDrive. But then what happens when an energy bill gets passed that changes the DST switchover by about a month? How does your car find out about it? I've seen some people suggest an FM radio station. Sure, but then there would have to be a universally accepted standard for such a situation, and further, you're not guaranteed to be in the same time zone as a particular FM radio station under all circumstances. The bottom line is that it's not as easy as you think, and is *much* easier to have you, the user, change your offset from GMT twice a year. Other devices that reset their time do so because they can, easily. Your car can't. (Now, with a telematics service like BMW Online or BMW Assist/Teleservice, they could theoretically reset your clock as long as you maintained a profile with your timezone, or BMW built a service that used the GPS in your vehicle to determine your location for purposes of setting time. But this probably isn't a really high priority, as one would imagine.)
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Originally Posted by JDN' date='Oct 31 2005, 10:45 AM
Looks like cars with NAV should be able to update the clock.
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#24
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Originally Posted by drjochen' date='Oct 31 2005, 09:43 AM
My $400 Garmin GPS set its clock right...and it knows what time zone its in.
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In BMW's case, they get the nav unit from Siemens VDO, the OS from Microsoft (Windows CE for Automotive Platforms), the GIS data from NAVTEQ, and all things considered, resetting the clock for daylight savings time is probably a very low priority.
I'm curious: will your Garmin correctly reset its time based on the energy bill changes? I'm betting it won't (unless you got a software update for it after the energy bill passed).
Originally Posted by JDN' date='Oct 31 2005, 09:45 AM
Looks like cars with NAV should be able to update the clock.
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Originally Posted by drjochen' date='Oct 31 2005, 11:07 AM
I thought the DST change in the energy bill doesn't go into effect until 2007?
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#27
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What's odd is that Windows (CE) devices have a built-in offline database for controling DST.
E.g. if you set up a PDA, choose London as the City and optionally tick DST, the database knows that DST runs between April and October, applying simple calendar rules for the switch on/off dates.
I can't think why CE for cars would have this functionality removed, unless BMW specifically requested it.
Does the 7 series auto-update?
E.g. if you set up a PDA, choose London as the City and optionally tick DST, the database knows that DST runs between April and October, applying simple calendar rules for the switch on/off dates.
I can't think why CE for cars would have this functionality removed, unless BMW specifically requested it.
Does the 7 series auto-update?
#28
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Originally Posted by m630' date='Oct 31 2005, 10:12 AM
[quote name='drjochen' date='Oct 31 2005, 11:07 AM']I thought the DST change in the energy bill doesn't go into effect until 2007?
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[/quote]Yes, it's March 11, 2007...I had updated my post after I realized that the change won't occur until then.
#29
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Originally Posted by browellm' date='Oct 31 2005, 10:12 AM
What's odd is that Windows (CE) devices have a built-in offline database for controling DST.
E.g. if you set up a PDA, choose London as the City and optionally tick DST, the database knows that DST runs between April and October, applying simple calendar rules for the switch on/off dates.
I can't think why CE for cars would have this functionality removed, unless BMW specifically requested it.
Does the 7 series auto-update?
E.g. if you set up a PDA, choose London as the City and optionally tick DST, the database knows that DST runs between April and October, applying simple calendar rules for the switch on/off dates.
I can't think why CE for cars would have this functionality removed, unless BMW specifically requested it.
Does the 7 series auto-update?
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I guess I'm wondering what going through the trouble to have the vehicle update itself for DST buys us, other than not having to change the offset from GMT twice a year, which takes about 15 seconds.
And Windows CE for Automotive Platforms doesn't necessarily share the same functionality with other CE/PocketPC devices. WinCE for Automotive is very targeted and customized to a manufacturer's specifications. That said, it may still contain the functionality...but again, it's my own personal opinion that this is a very low priority item globally. Others may disagree.
#30
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Originally Posted by das' date='Oct 31 2005, 04:15 PM
[quote name='browellm' date='Oct 31 2005, 10:12 AM']What's odd is that Windows (CE) devices have a built-in offline database for controling DST.
E.g. if you set up a PDA, choose London as the City and optionally tick DST, the database knows that DST runs between April and October, applying simple calendar rules for the switch on/off dates.
I can't think why CE for cars would have this functionality removed, unless BMW specifically requested it.
Does the 7 series auto-update?
E.g. if you set up a PDA, choose London as the City and optionally tick DST, the database knows that DST runs between April and October, applying simple calendar rules for the switch on/off dates.
I can't think why CE for cars would have this functionality removed, unless BMW specifically requested it.
Does the 7 series auto-update?
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I guess I'm wondering what going through the trouble to have the vehicle update itself for DST buys us, other than not having to change the offset from GMT twice a year, which takes about 15 seconds.
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[/quote]Not sure I understand you 100%. You have a check box that lets you apply DST, or not.
Personally, I don't have a problem changing the time twice a year, but the thread is at 28 replies and counting