Daylight Savings Time and your Kindle

Daylight Savings Time and your Kindle

In my area, we were supposed to turn our clocks back an hour at 2:00 AM this morning.

That’s enthusiastically stated as “getting an extra hour’s sleep.”  That may be true…if you don’t have cats or small children.  🙂  Their internal clocks don’t realize the time change, and they may get you up anyway.

Of course, you have an internal clock, too, and may be mad at yourself for not sleeping in.  Would you actually have set the alarm for this morning?  If you didn’t, did you wake up, look at the clock, realize it was too early, and go back to sleep?

Maybe you did…I can’t do that very well, personally.

Oh, and “turn back the clock”?  Not a very accurate description of what we do with a digital clock.  With an analog clock, yes.  🙂

Your Kindle has an internal clock, too.  It maintains the time, and uses that for a couple of important things…sort order for “most recent” being one of the ones you’ll notice the most.

So, how does your Kindle adjust to Daylight Savings Time or the return to Standard Time (or “Summer Time” or whatever you call it locally)?

There are two answers to that, depending on how you connect to the internet on your Kindle.

3G (Kindle 1, Kindle 2, Kindle DX)

Kindles that connect to the internet (and Amazon’s Whispernet) using 3G get their time because a cell tower tells them what time it is.  That’s the way your cell phone works as well.   You have to reconnect to the network for the Kindle to get the updated time.  I said “internet” above because you can reportedly get a time signal from a tower with which you can not establish a data connection.  Even if you can’t download books through the 3G (due to a weak signal), try connecting anyway to get an updated time signal.

Home-Menu-Sync & Check for Items

What do 3G device users do when they can’t connect to a network?  Their clocks are wrong and stay wrong…that’s been a problem since the K1.

Note that if you connect to a cell tower that has a different time zone than the one you want to be on, it’s still going to change.  That can be confusing when you travel, since you may not keep connecting and disconnecting to keep your clock correct.  You also might be near enough to a powerful tower from another time zone so that it sets it to that other time zone.

Wi-Fi (Kindle 3s)

When the new 6″ Kindles (the “Kindle 3s”, in community parlance) were released, they gave the Kindle a new way to connect…wi-fi.  One model has both 3G and wi-fi, the other has just wi-fi.

Well, wi-fi doesn’t have a time signal like a 3G tower does.  Amazon couldn’t rely on that to set the time.

What did they do?  Allow manual time-setting.

Home-Menu-Settings, Next Page, Device Time, Set Manually

If you have the dual access model, you can use either technique.

Daylight Savings Time isn’t the only reason you might set your clock.  When your Kindle resets, it may lose track of the time, for example.

Enjoy your “extra hour of sleep”!  I’ve already fed the cats and dogs…  😉

This post by Bufo Calvin originally appeared in the I Love My Kindle blog.

4 Responses to “Daylight Savings Time and your Kindle”

  1. Rita Says:

    Took my Kindle 3 out of sleep mode this morning and the time was correct. It wasn’t connected to either 3G or Wi-fi. Looks like Amazon found a way to make it happen.

    • bufocalvin Says:

      Thanks for writing, Rita!

      I have heard that Amazon can remotely connect when you don’t have the wireless on…but this one seems a bit odd to me. They could have “taught” the Kindle when DST was going to end…but that’s different in different states.

      Thanks for letting me know!

  2. Rob Poole Says:

    Just wanted to say, there is actually a well established protocol for obtaining time (and date) info over the Internet, and therefore over WiFi networks — it’s called NTP (an abbreviation of Network Time Protocol, not to be confused with NNTP which is Net News, aka Usenet). With NTP, you only need an active network connection and the address of an NTP server.

    There are many public NTP servers operating at different “layers” (basically, some servers are running at the root of the whole thing and use reference clocks from GPS or an atomic clock, while other servers simply refer to one of the servers running at a lower layer). Apple even operates their own NTP servers for Mac/iPhone/iPad customers. I’m surprised, since the Kindle is reportedly Linux based, that Amazon didn’t simply add support for obtaining NTP data to the Kindle in WiFi mode.

    Knowing Amazon’s business, I’d also be shocked if they were not using NTP in their many data centers — clock drift between servers can be a bad thing.

    All that said, my Kindle (3rd gen) does seem to be pulling the time and time zone data from the local AT&T tower. Unfortunately, it’s pulling the wrong time zone — I am in the Phoenix Metro area, but the time zone is coming back as Los Angeles / Pacific Daylight Time. Since Arizona does not do Daylight Savings Time, this could prove interesting during some parts of the year, though the misconfiguration might only be the cell tower near my office. Right now, the time and date are correct because MST is equivalent to PDT, and we’re on MST (not MDT).

    Incidentally, I found out which cell tower I’m talking to using a little trick. Go into Settings (Home -> Menu -> Settings) and type 611 to get information — it’ll tell you your IP address on one of the pages, and a whole bunch of technical data. It updates live, so some pages may disappear on you as you’re looking at them. You can also type 311 to actually get a dialog showing all the available networks in the area, and which one you’re currently on. (Right now, I’m seeing AT&T 3G, which is checked, then AT&T 2G and T-Mobile 2G.) The default selection is to let the Kindle automatically detect and switch the network, and I recommend you leave that selection enabled.

    As for typing numbers on the Settings screen, you can use the Sym button to pop up the symbol dialog, or you can use Alt + buttons on the top row of the keyboard to type numbers. (Alt+Q = 1, Alt+W = 2, Alt+P = 0, etc.)

    • bufocalvin Says:

      Thanks for writing, Rob!

      I appreciate you sharing your technical knowledge about NTP.

      Yes, I’ve written about typing 611, 411, and 311. The 611 will give you the latitude and longitude of the cell tower (only when you are on 3G, of course…not using wi-fi). That screen, as you note, refreshes quickly…so it will take significantly more battery than reading, I assume. This post talks about that:

      I’ve also written about the numbers. This post has the complete sequence:

      If you are getting to the blog online (as opposed to on your Kindle), there is a searchbox, so you can find that earlier information. However, always feel free to post…it helps people to see it again and to see it expressed differently. 🙂


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