time

45 Articles

Globe-Shaped World Clock Is A 3D-Printed Mechanical Marvel

August 12, 2024 by 5 Comments

Time zones are a complicated but necessary evil. Humans like the numbers on the clock to vaguely match up with what the sun is doing in the sky outside. To that end, different places in the world keep different time. If you want to keep track of them in a very pretty fashion, you might consider building a fancy and beautiful World Clock like [Karikuri] did. 

The design is based around a globe motif, mimicking the world itself. Only, on the surface of the globe, there are clock faces instead of individual countries. Each clock runs to its own time, directed by a complicated assemblage of 3D-printed gears. Mechanical drive is sent to the globe from a power base, which itself carries a mechanical seven-segment display. This too can display the time for different regions by using the controls below. It’s also useful for setting the clock to the correct time.

It’s a little difficult to follow the build if you don’t speak Japanese. However, quality subtitles are available in English if you choose to enable them.

We’ve seen [Karikuri’s] work before. We’ve also featured a great many world clocks over the years, including this particularly beautiful example that tracks night and day. Just don’t expect it to keep track of moon time. Video after the break.

Continue reading “Globe-Shaped World Clock Is A 3D-Printed Mechanical Marvel” →

Climate Change May Make Days Longer

July 31, 2024 by 31 Comments

For those who say there’s never enough time in a day, your wish for more time is getting granted, if ever so slightly. Scientists have now found a new source of our days getting longer — climate change.

You may have already been aware that the length of the day on Earth has been getting longer over time due to the drag exerted on our planet by our friendly neighborhood Moon. Many other factors come into play though, including the Earth’s own mass distribution. As the Earth warms and polar caps melt, the water redistributes to the Earth’s equator causing it to slow more rapidly.

In the worst-case scenario, RCP8.5, it would result in climate-related effects to planetary rotational velocity even larger than those caused by lunar tides. Under that scenario, the earth would probably be a less pleasant place to live in many other ways, but at least you’d have a little more time in your day.

While we’re talking about time, we wonder what ever happened to getting rid of Daylight Savings in the US? If you long for a simpler time, perhaps you should take up repairing mechanical watches and clocks?

Saving A Clock Radio With An LM8562

March 28, 2024 by 10 Comments

Smart phones have taken the place of a lot of different devices especially as they get more and more powerful. GPS, music and video player, email, and of course a phone are all functions tied up in these general-purpose devices. Another casualty of the smart phone revolution is the humble bedside alarm clock as its radio, alarm, and timekeeping functionalities are also provided by modern devices. [zst123] has a sentimental attachment to the one he used in the 00s, though, and set about restoring it to its former glory.

Most of the issue with the clock involved drift with the timekeeping circuitry. Since it wasn’t accurately keeping the time anymore, losing around 10 minutes a day, the goal to save it was to use NTP to get the current time and a microcontroller to make the correction automatically. Rather than replace everything in the clock except the display, [zst123] is using the existing circuit board and adding an ESP8266 to grab the time from the Internet. A custom driver board reads the current time displayed on the clock directly from the display itself and then the ESP8266 can adjust it by using the existing buttons through a relay wired in parallel.

Using the existing circuitry was certainly a challenge especially since the display was multiplexed, but the LM8562 that came with these clock radios is a common and well-documented chip for driving displays like this, giving [zst123] a leg up over something unlabeled or proprietary. Using NTP is certainly a reliable and straightforward way of getting the current time too but there are a few other options for projects like these like using GPS or even a radio signal.

How Many Time Zones Are There Anyway?

February 14, 2024 by 38 Comments

Nowadays, it’s an even bet that your newest project somehow connects to the Internet and, thus, to the world. Even if it doesn’t, if you share your plans, someone might reproduce your creation in some far distant locale. If your design uses time, you might need to think about time zones. Easy, right? That’s what [Zain Rizvi] thought until he tried to deploy something that converted between timezones. You can learn from his misconceptions thanks to a detailed post he provides.

You might think, “What’s the big deal?” After all, there’s UTC, and then there are 12 time zones ahead of UTC and 12 time zones later. But that’s not even close to true.

As [Zain] found out, there are 27 hours in a full-day cycle if you count UTC as one hour. Why? Because some islands in the Pacific wanted to be on the wrong side of the International Date Line. So there are a few extra zones to accommodate them.

You can’t even count on time zones being offset by an hour from the previous zone. Several zones have a half-hour offset from UTC (for example, India’s standard time is 5.5 hours from UTC). But surely the offset is always either a whole number or a number where the fractional part is 0.5, right?

Um, no. Nepal wants the sun to be directly over the mountain at noon, so it offsets by 45 minutes! [Zain] wonders — as we do — what would happen if the mountain shifted over time? Until 1940, Amsterdam used a 20-minute offset. Some cities are split with one half in one time zone and another in the other.

Of course, there are the usual problems with multiple names for each zone, both because many countries want their own zone and because the exact same zone is different in different languages. Having your own zone is not just for vanity, though. Daylight savings time rules will vary by zone and even, in some cases, only in certain parts of a zone. For example, in the United States, Arizona doesn’t change to daylight savings time. Oh, except for the Navajo Nation in Arizona, which does! Some areas observe daylight savings time that starts and ends multiple times during the year. Even if you observe daylight savings time, there are cases where the time shift isn’t an entire hour.

Besides multiple names, common names for zones often overlap. For example, in the United States, the Eastern Standard Time zone differs from Australia’s. Confused? You should be.

Maybe we should have more respect for multiple time zone clock projects. We’ve noticed these problems before when we felt sorry for the people who maintain the official time zone database.

Kinetic Clock Is A Clean Modern Way To Tell Time

January 16, 2024 by 11 Comments

Hackers and makers aren’t usually too interested in basic round analog clocks. They tend to prefer building altogether more arcane and complicated contraptions to display numbers for the telling of time. [alstroemeria] did just that with this nifty kinetic clock build.

The basic concept of the kinetic clock is to have a flat plate, which individual segments raise out of to create a physical (instead of illuminated) 7-segment display. This is achieved with servos which push the segments in and out using a small rack mechanism. It’s not a sophisticated build; it simply uses 30 servos to handle all the segments needed to tell time. Thus, the Arduino Mega was the perfect tool for the job. With a sensor shield added on, it has an abundance of IO, driving a ton of servos is a cinch. There’s also a DS3231 real time clock to help it keep accurate time.

Incidentally, it’s a hefty thing to print, according to YouTuber [Lukas Deem] who replicated the project. It took around 85 hours to print, and a total of 655 grams of filament – not counting mistakes and trashed parts.

And if you think you’re having deja-vu, you might well be. We’ve seen a take on this exquisite design before. We liked it then, and we like it now.

Overall, it’s a stylish build that looks as good as your 3D printer’s output will allow. A resin printer would be a massive boon in this regard. Video after the break.

Continue reading “Kinetic Clock Is A Clean Modern Way To Tell Time” →

Simulating A Time-Keeping Radio Signal

January 14, 2024 by 14 Comments

As far as timekeeping goes, there’s nothing more accurate and precise than an atomic clock. Unfortunately, we can’t all have blocks of cesium in our basements, so various agencies around the world have maintained radio stations which, combined with an on-site atomic clock, send out timekeeping signals over the air. In the United States, this is the WWVB station located in Colorado which is generally receivable anywhere in the US but can be hard to hear on the East Coast. That’s why [JonMackey], who lives in northern New Hampshire, built this WWVB simulator.

Normally, clocks built to synchronize with the WWVB station include a small radio antenna to receive the 60 kHz signal and the 1-bit-per-second data transmission which is then decoded and used to update the time shown on the clock. Most of these clocks have internal (but much less precise) timekeeping circuitry to keep themselves going if they lose this signal, but [JonMackey] can go several days without his clocks hearing it. To make up for that he built a small transmitter that generates the proper timekeeping code for his clocks. The system is based on an STM32 which receives its time from GPS and broadcasts it on the correct frequency so that these clocks can get updates.

The small radio transmitter is built using one of the pins on the STM32 using PWM to get its frequency exactly at 60 kHz, which then can have the data modulated onto it. The radiating area is much less than a meter, so this isn’t likely to upset any neighbors, NIST, or the FCC, and the clocks need to be right beside it to update. Part of the reason why range is so limited is that very low frequency (VLF) radios typically require enormous antennas to be useful, so if you want to listen to more than timekeeping standards you’ll need a little bit of gear.

A wooden digital clock with a metal knob on one end

Hackaday Prize 2023: Stretch Your Day With This 29-Hour Clock

September 24, 2023 by 9 Comments

Modern life can be stressful. Many of us struggle to balance work, family, exercise, and an ever-growing list of hacking projects, all of which claim our attention during the day. If you sometimes feel that those 24 hours just don’t cut it, you might be in luck: [HIGEDARUMA] has built a clock that can stretch your day by up to five hours.

Sadly, [HIGEDARUMA] hasn’t invented time travel (yet). What his clock does instead is slow down its own pace in the evening to push back the midnight hour. When it finally does reach 12:00 a.m., the clock’s pace is accelerated to ensure it’s back in sync with the rest of the world by six in the morning. It might seem silly, but there is a certain logic to it: [HIGEDARUMA] explains that evenings felt much longer when he was a child and that he would like to try and experience that again. Our sense of time may change over our lifetime, even if the actual passage of time doesn’t.

Timescales aside, the 29-hour clock is a neat piece of work from a hardware point of view. The case is made from 4 mm laser-cut MDF with wood-grain foil on the outside. Inside, there’s an ESP32 to run the show, along with an RTC module and three four-digit seven-segment LED displays. A chunky “volume” knob on the front lets you choose how much you’d like your day to be stretched.

We’ve seen clocks with non-linear dials before, as well as extremely linear ones, but this might be the first one with a non-constant pace. It makes us wonder what the passage of time feels like for those frozen in ice for 46,000 years.

Continue reading “Hackaday Prize 2023: Stretch Your Day With This 29-Hour Clock” →