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Why does the alarm clock snooze button give you nine extra minutes, not ten?
- failrate 13y agoI have a problem with this explanation, because on my grandmother's ancient electromechanical clock (with radium painted hands), the snooze alarm interval was user-defined between a few minutes to almost an hour. I'm leaning towards someone cleverly using the numeric rollover to trigger the interval, and then every subsequent digital clock cargo culting the design.
- happywolf 13y agoI always wish iOS allows me to set the snooze interval...
- therandomguy 13y agoI thought it was to disorient you a bit. If you typically snooze three times you know you have to be out of the bed at 8:00 sharp (with 7:30 original). Easy for your brain to latch on to that. Now with 9 mins…
- aeontech 13y agoI can do multiplication in half-conscious state easily if it means a few more minutes of precious, precious sleep... Besides you really just need to remember how to do subtraction, not even the multiplication table var snooze = 3 snoozety (30) minutes minus snooze (3) minutes = twenty seven Now, if the alarm clock required you to solve a calculus problem, that'd be a bit more challenging :)
- DanBC 13y ago> "Or maybe, since the clock is counting (typically) the power cycles from the wall socket, it's because [...] > Engineer's comment: Nice try, bub, but clocks don't count that way. What? Some clocks do count that way. That's why you can buy converters. http://www.electric-clocks.co.uk/60hz50hzfrequenc.html http://www.electric-clocks.co.uk/60hz50hzfrequenc.html > Thiis module takes the 60Hz input and produces a 50Hz output to ensure the clock keeps the proper time. The module is supplied with 9vac via a UL listed power supply adapter. The clock has had it's coil rewound to work at 9vac. > No changes to the movement - no altered wheelwork. If the clock is ever required to run in the UK it is as simple as providing 9vac from a UK 50Hz power supply and bypassing the convertor. https://en.wikipedia.org/wiki/Electric_clock#Synchronous_electric_clock https://en.wikipedia.org/wiki/Electric_clock#Synchronous_ele... > A synchronous electric clock does not contain a timekeeping oscillator like a pendulum, but instead counts the oscillations of the AC utility current from its wall plug to keep time. Here's a nice page telling you how to build one. It has plans for both 50 Hz and 60 Hz. http://sound.westhost.com/clocks/sync.html http://sound.westhost.com/clocks/sync.html
- codezero 13y agoedit: It sounds like the first alarm clock with a snooze might have been synchronous so maybe it's worth thinking more about that :) http://en.wikipedia.org/wiki/Telechron http://en.wikipedia.org/wiki/Telechron http://blog.onlineclock.net/evil-snooze-clock-history/ http://blog.onlineclock.net/evil-snooze-clock-history/ It's a bummer the Wikipedia article for Alarm clocks cites the straight dope article which links to some suggestive information that is totally missing now. It's too bad that Wikipedia doesn't store source information that is important for verifying the statements in articles in case the linked source disappears (or does it?) originally, and probably wrong: Yeah, some clocks used this, but I don't think it was most clocks and unless the first clock with a snooze functionality was this type, it doesn't give any more insight into why 9 minutes was chosen.
- Groxx 13y ago>It's too bad that Wikipedia doesn't store source information that is important for verifying the statements in articles in case the linked source disappears (or does it?) Good reason to donate to www.archive.org :) It's probably accessible there, and the citation should include a date you can rewind to. Not that that's ideal, but it's at least verifiable, and probably available now if not forever.
- abrahamsen 13y agoWikipedia encourage editors to use archive.org. http://en.wikipedia.org/wiki/Wikipedia:Using_the_Wayback_Machine http://en.wikipedia.org/wiki/Wikipedia:Using_the_Wayback_Mac...
- nwh 13y agoSo many devices rely on the timing of the waves that the generating companies actually keep count and then adjust the speed to make up any they might have missed!
- wyager 13y agoThat's not at all why grid timing is so precise. Multiple generation systems feed into the same grid. If they're out of phase by even a few milliseconds, that translates to huge power losses. If power generation companies didn't synchronize to high precision, they would lose a lot of power and probably break some equipment.
- codezero 13y agoThis still skips the reasoning for even an imprecise 9 or 10 minutes. What information guided that decision? Ignoring the precision is a separate practical issue.
- jarrett 13y agoI can imagine it went something like this: Engineer: "Hey boss, how long did you want the snooze timer to run?" CEO: "Oh, I don't know. Not too long, not too short." Engineer: "What does that mean? Like 10 minutes or so?" CEO: "Sure, I guess that would be fine. Just get it done." Since this is an alarm clock, not a nuclear power plant, it's entirely conceivable that the decision was made very casually. It could have just been someone's gut feeling that 9 or 10 minutes felt right.
- codezero 13y agoSounds about right, but it would be awesome to know for sure, but maybe I should be getting something done too :)
- deleted 13y ago[deleted]
- pgrote 13y agoA shame you cannot get to the old link in the article. https://web.archive.org/web/20021001101305/http://users.rcn.com/jayman/ https://web.archive.org/web/20021001101305/http://users.rcn....
- toomuchtodo 13y agohttp://web.archive.org/web/20000830091714/http://www.ultranet.com/~jayman/ http://web.archive.org/web/20000830091714/http://www.ultrane...
- ctdonath 13y agoI want to know why the alarm clock off button is built like something you'd not want to use. Snooze is a big fat easy button; off is a small switch hidden among other switches and usually on the bottom back of the device, requiring turning off to stop the alarm and then turning the switch back on to re-enable it for the next day. Once I'm awake, I want to shut the alarm up - period - without having to find and fiddle with a hidden control. Or am I seriously missing something obvious about standard cheap alarm clocks?
- dlubarov 13y agoI think the idea is to make it harder to semi-consciously turn off the alarm clock before you're really awake.
- _wmd 13y agoBecause for people like me, unconscious zombie-like bears who will dig through concrete walls with bare hands in order to quiesce the source of the disturbance of my crucial slumber, while maintaining no memory of the demolished wall should I be successfully woken 10 seconds later, easily shut off devices simply have no effect. I've woken up a few times on the floor curled around the power cord to the alarm clock, torn from the wall (or to find a phone in 15 pieces and a new dent in the wall).. many, many people like me
- MiguelJones 13y agoMaybe it's just a simple matter of whoever implemented the snooze functionality picking 9 minutes as the value. The one minute difference between 9 and 10 minutes is probably negligible.
- dwrtz 13y agoIt leaves you with an extra minute to decide if you're going to hit snooze again.
- Groxx 13y agoDunno. All the alarms I've owned have been 6 or 7 minutes. Another question: why does the alarm clock blare non-stop until you turn it off, rather than beeping a couple times and then going silent, giving you a moment to get up and turn it off without annoying the living hell out of everyone who doesn't have to get up? Current theory: alarm clock designers never marry.
- colanderman 13y agoMy wife's alarm clock works that way. It's pleasant yet effective.
- Groxx 13y agoMy wife and I have mostly switched to the Jawbone Up since it's a silent, vibrating alarm, and we each have a different one. Audible is now the backup. But! What alarm is this? It sounds wonderful. Mine is pretty old and starting to die / possibly flaky, I might have to pick one up.
- colanderman 13y agoIt's not standalone sadly; it's part of a basal body temperature monitor. Yet somehow they got right what actual alarm clock manufacturers couldn't…
- kijin 13y agoMe too. This is the first time I've ever heard of alarm clocks with 9-minute snooze intervals. The TIMEX clock I've been using since college has 8-minute intervals, and the alarm clock app I have on my phone has 10-minute intervals by default.
- TeMPOraL 13y agoDepending on how tired (or drunk) I went to bed the previous night and how much time I gave myself for sleep, it might take even a few minutes for me to finally wake up to the alarm signal. Anything short would be totally ineffective for me. Also, this ensures the alarm clock does its job - either you wake up yourself, or your angry family members wake you. Both ways, you get up when you wanted.
- Steuard 13y agoI always guessed that they wanted something around 10 minutes, but they wanted more than one visible digit to change each time to make it more obvious that time had passed. (That is, a sleepy person might be more likely to mistake "7:20" for "7:00" than they would be if they saw "7:18".) But that wouldn't be relevant with old analog alarm clocks, which evidently had a 9-10 minute snooze, too.
- atoponce 13y agoI can't say if this is why it's 9 minutes, instead of 10, but when the alarm goes off, and I hit the snooze, my brain is anything but fully conscious. So, I see the time "06:00" then "06:09" rather than "06:10", and I know the time has changed- because of the 9. At the next interval, it's "06:18" rather than "06:20". Again, an obvious time differential for my brain. Instead of just 1 number changing every ten minutes, 2 numbers are changing. 06:00 06:09 06:18 06:27 06:36 06:45 06:54 07:03 ... etc. Versus: 06:00 06:10 06:20 06:30 06:40 06:50 07:00 Not enough numbers are changing for my brain to latch on in its semi-conscious awake state, if the time is only changing by 10 minutes. Changing by 9, and it's clear the time has changed, and it's a new time. Thus, I'm not thinking only 10 minutes have passed, when the truth is that 40 minutes has actually passed.
- tempestn 13y agoHuh, never thought of that. That probably is kinda handy.
- contingencies 13y agoThis seems closer to engineer-thought reality, IMHO. Also, some people like to snooze multiple times... a low number of times, to be precise. They do this as a regular thing. If I were such a person and I were to snooze thrice, I would know I am really in need of getting up if 30 minutes has elapsed. There is an up to one minute procedural loss on sorta-wake-up, activate-limb, smash snooze button, go back to bed. So I know I'm definitely not sleeping over my 30 minutes of triple-snooze allowance if I have a 9 minute timer. (Yes, the timer could be set from the trigger time rather than the re-snooze time, but at least some ancient embedded devices probably did not function in this way) To further compound this line of thinking, we should remember that getting out of bed is not the only use for timers. Another would be kitchen timers where people might really, really, really want to get the pie out before it burns and some default allowance for human fuzzy foibles is therefore a useful feature. Perhaps we should replace the title of this post with: Engineers: "Nine; it made sense at the time".
- cstrat 13y agoThis makes the most sense to me!
- Juha 13y agoHow about this for a reason: One of the first big snooze clock manufacturers choose 9 minutes for some random reason and the rest followed thinking: "There must be a reason they choose 9 minutes, it sounds specific. Lets have our snooze be 9 minutes too." I was expecting find some some highly researched psychological quirk to be the reason in the post. I guess reality is just more random and coincidental. Reminds me of the way QWERTY came to be the standard (https://en.wikipedia.org/wiki/QWERTY#History_and_purposes https://en.wikipedia.org/wiki/QWERTY#History_and_purposes).
- tempestn 13y agoI had always just assumed it must have been an ease of implementation thing. (Explanation 8.) Their suggestion that you could just check the 10s column instead of the 1s is misleading. You would have to test both the 10s and the 1s column to get a 10 minute differential, unless the original alarm time happened to be a multiple of 10.
- MRSallee 13y ago8:00:00 am alarm clock begins beeping 8:00:15 I actually begin waking up 8:00:45 I manage to get up and silence the dumb machine 8:10:00 alarm wakes me up again after initial snooze, ten minutes after I intended to be awake If the snooze went in ten minute increments, and a person was fond of snoozing, after a handful of snoozes the time delay between alarm sounding and snoozing would add up and throw off the mental calculation. "I've hit the snooze five times, it must be 8:50, oh shit it's actually 8:55, FML," versus, "I've hit the snooze five times, it must be 8:50, oh hey it's actually only 8:47."
- itchitawa 13y agoThis is also my pet theory too. You can mentally count and err on the safe side.
- IbJacked 13y agoThat's been my theory, as well.
- kseistrup 13y ago+1
- hrkristian 13y agoThat's a good theory. I have multiple alarms on my phone, as sometimes I'll turn off an alarm completely in my sleep. I put these alarms teen minutes apart, call it OCD. Snooze time of nine minutes makessense a lot of sense fire my part.
- andyhmltn 13y agoI do this. I set one alarm for an hour before I'm meant to be up (I usually don't remember this), one half an hour before, one on the actual time and then in smaller and smaller increments until I'm so annoyed with turning it off that I just get up.
- hrkristian 13y agoThat's a good theory. I have multiple alarms on my phone, as sometimes I'll turn off an alarm completely in my sleep. I put these alarms teen minutes apart, call it OCD. Snooze time of nine minutes makessense a lot of sense fire my part.
- platypii 13y agoI have always assumed it was to reduce the likelihood of conflicts with future alarms. For example if I set alarms at 8:00 and 9:00, if I've been snoozing the 8:00 alarm, and snooze is 10 minutes, the two alarms will both fire at 9:00. With 8 or 9 minute intervals that is much less likely, and so its easier to see that maybe they are two different reminders. This probably applies more to phones than old school alarm clocks however.
- koobz 13y agoNine is great. I snooze 4 times and it's 4 minutes more time I have than if it were 10 minute intervals. That's 4 extra minutes to ride my bike to work on time for the daily standup at my startup. Now I suppose I could just set my clock 36 minutes later and get 36 minutes of quality sleep. But I think I actually enjoy those short snooze button dreams. And I savour every minute. Again and again and again and again.
- tsotha 13y agoI always assumed this was a function of hardware on the original snooze-enabled digital clocks. If you reset a decade counter chip (like the CD4017), you get a rising edge on the carry out pin after nine clocks.
- BarkingOven 13y agoI'll tell you exactly why it's nine minutes. Because in the olden days where everything was made with discrete components, the math of 9 minutes is WAY cheaper. Let's say it's 6:00, and you hit the snooze button. Save the current value of the minute minus 1, into a comparitor, Trigger the alarm when the comparitor goes off automatically. If you save the current value into the comparitor, the alarm triggers immediately. Now you need to add delay logic. Just use current minus 1, since it's only a few half-adders. You can't use the high order minute digit because then your snooze length will depend on your current low order minute digit. Any logic to compensate starts adding a multiple of the number of components required.
- sajidnizami 13y agoYour argument makes most sense around here :)
- gojomo 13y agoThank you, I would bet on this. Examining an early digital clock with 9-minute snooze could probably confirm that the 9 minutes is implemented using some smaller number of components than any 10-minute system could be. I also vaguely recall that such on such clocks, the alarm itself (if not silenced) would tend to run for 9 minutes before self-silencing. The same logic might apply: it's the longest finite interval that doesn't require some sort of multi-digit carry-logic. I wouldn't be surprised if early circuit layouts even made it so that the wiring to toggle some [digit ± 1] triggering state was shortest/cheapest, in a circular arrangement, compared to any other potential offset. (I don't even think there was anything binary in the earliest digital-display clocks, rather some [10m, 6h, 24h] or even [10m, 6h, 12h, 2meridiem] cyclical counters.)
- mtdewcmu 13y agoThis rings true.
- mehwoot 13y agoIt was established in the age of mechanical clocks. Because of the way the gears were generally configured, the two sane options were 9 minutes or a bit more than 10. They chose 9. Digital clocks followed suit.
- striderhiryu 13y agoMaybe just because it takes around one minute from the time the alarm starts to ring and the time the sleepy-head presses the button and eventually gets up. Better have a minute earlier than later.
- erichurkman 13y agoI prefer to subscribe to the idea that it was an off-by-one error myself.
- badman_ting 13y agoMoral of the story: Worse is better :)
- blahedo 13y agoI've been using my cell phone as primary alarm clock for years, and it always bugged me, for reasons I can't even articulate, that the snooze interval was "wrong"---ten minutes on one phone, five on another. When I finally got my Android phone and could find my own alarm app that let me configure the snooze time, I was inordinately pleased. 9 minutes it is. :) (Alarm Clock Plus, by the way---has a few other nice UI features as well.)
- benatkin 13y agoIs there a good documentary about alarm clocks?
- splinter_head 13y agoOn an old alarm clock of mine, the snooze started at 9 minutes, then went down to 8, then 7 and so on. this allowed exactly 45 minutes of snooze. Something from that may have been brought into modern alarm clocks?
- inevitable 13y agoyou sure it's exactly 9 minutes ? I always thought it was 9 min and 59 seconds and 999- ms Because as soon as you press the button, it begins to countdown the 10 minutes.
- zvrba 13y agoAm I the only person who manages to wake up almost instantly and never uses the snooze function?
- jbrooksuk 13y agoI was wondering this, just this morning as I hit snooze. Thanks HN, you've done it again!
- napolux 13y agoMy alarm clock gives me 8 minutes. Now what?
- mrweasel 13y agoEvery single alarm clock I've had has given me seven, and I always wondered why.
- rgf 13y agoI always thought it was 9 minutes to have 10 minutes of total delay with 1 minute ring time. So that if you don't do anything it keeps ringing every ten minutes. If you hit snooze it just stops ringing earlier. I think it's optimised to ring periodically in the worst case scenario (when you don't wake up). With earlier snooze it's just easier to keep the 9 minutes worst case implementation, instead of taking into account the time you hit snooze and adjust the snooze time to reach the 10 minutes total delay between rings.
- jalanb 13y agoI came to the comment page to say that it's pages like that that make me grateful for the internet. Then I read the comments - actually, it's pages like this that make me grateful for the internet.
- smoyer 13y agoA nice parallel to the question "Why do I click on a floppy disk to save my file?"
- jmpe 13y agoOh, there are a few more like that: - there's a very good chance that the touch-pad in your new laptop uses the PS/2 protocol to communicate with the system - why do I need to address cylinders/heads/sectors in a flash block device? I can understand sectors (block addressing) but cylinders and heads? It's FAT/EXT4 legacy, but the translation layer is still there in many OS-es. - I recently wrote a driver for an LCD. I could have sworn I was accessing a CRT: front porch, h-sync pulse, back porch, v-sync, ...
- brechin 13y agoMy clock DOES have a ten-minute snooze. I know previous clocks I've used had a 9-minute snooze, but currently when my alarm goes off at 6:00, I hit snooze a few seconds later, then a few seconds after the clock displays 6:10, it alarms again.
- redblacktree 13y agoMine is adjustable. I have it set to 3 minutes. I still often snooze 5-6 times, but now it costs me ~20 minutes instead of an hour.
- aiaf 13y agoI set the snooze on my phone alarm to 20 minutes, which is the standard for the Uberman polyphasic sleep practice. Feels good enough.