The returned instants from Clock work on a time-scale that ignores leap seconds, as described in Instant. If the implementation wraps a source that provides leap second information, then a mechanism should be used to "smooth" the leap second. The Java Time-Scale mandates the use of UTC-SLS, however clock implementations may choose how accurate they are with the time-scale so long as they document how they work. Implementations are therefore not required to actually perform the UTC-SLS slew or to otherwise be aware of leap seconds.


A perfect piece for nightstands and home office desks, this radio alarm clock tunes to your favorite stations as it keeps an eye on the hour. Its bright red LED numbers are easy to read from afar, while the repeating nine-minute snooze is sure to become your new best friend on lazy Sunday mornings. This digital clock includes memory for up to 20 radio stations and includes an audio input for smartphones and MP3 players. Though this radio plugs into your wall, it also runs on two AAA batteries...
There’s a lot of science when it comes to sleeping, and there’s never a short supply of sleep-related tests going on. One of our favorite electronic brands here on Gear Hungry has made the most effective clock (in our humble opinion), and it’s the #8 pick: Philips Wake-Up HF3505. Slow light build mimics the sunrise, and gently pulls you out of a sleep-like trance before hitting you with some serious sound. Between price, effectiveness, and the fact that we didn’t have to chase it around the room (sorry Clocky, we’re not morning people), we absolutely loved this one.
This color-changing option features a radio, built-in wake-up tones, Bluetooth music streaming (so you can wake up to your favorite playlist), and USB-charging capacity to keep your phone juiced. You can preset two alarms, cycle through colors, and snooze, and even use the alarm clock's speakerphone and microphone functions to answer phone calls from paired devices. Basically, this clock does everything except your laundry.
Clock radios are powered by AC power from the wall socket. In the event of a power interruption, older electronic digital models used to reset the time to midnight (00:00) and lose alarm settings. This would cause failure to trigger the alarm even if the power is restored. To solve this issue, they trigger the alarm at 00:01 after a reset, so that at least the user is able to correct the clock and alarm settings. Most of the recent clock radios use a battery backup to maintain the time and alarm settings. Some advanced radio clocks (not to be confused with clocks with AM/FM radios) have a feature which sets the time automatically using signals from atomic clock-synced time signal radio stations such as WWV, making the clock accurate and immune to time reset due to power interruptions.
Until advances in the late twentieth century, navigation depended on the ability to measure latitude and longitude. Latitude can be determined through celestial navigation; the measurement of longitude requires accurate knowledge of time. This need was a major motivation for the development of accurate mechanical clocks. John Harrison created the first highly accurate marine chronometer in the mid-18th century. The Noon gun in Cape Town still fires an accurate signal to allow ships to check their chronometers. Many buildings near major ports used to have (some still do) a large ball mounted on a tower or mast arranged to drop at a pre-determined time, for the same purpose. While satellite navigation systems such as the Global Positioning System (GPS) require unprecedentedly accurate knowledge of time, this is supplied by equipment on the satellites; vehicles no longer need timekeeping equipment.
“This alarm clock will wake you up! I’m totally deaf in one ear and partially deaf in the other. Alarm clocks I used before I purchased this one might as well have been turned off if I happened to have my good ear on the pillow when they went off. This one is loud! Now having said that, its loudness is adjustable, and I found that a low setting of two works just fine for me, but if I am particularly concerned about being awakened, I also set the vibrating disk, which is slipped under the mattress. Believe me: Even if you are totally deaf in both ears, this will wake you up. I was skeptical about the vibrator because I have a thick mattress, but it works with no problem at all! I wholeheartedly recommend this alarm clock for anyone who is hearing impaired.”
With the application of the synchronous electric motor to clocks in 1918, domestic electric clocks became popular. A synchronous electric motor runs in step with the frequency of the electric power source, which in most countries alternates at 60 hertz (cycles per second). The electric motor is coupled to a reduction gearing that drives the clock hands at the correct rate.

Who doesn't love an alarm clock that verbally lets you know it's time to get up and start your day? Step aside, Siri, because "Reminder Rosie" is where it's at. You can easily record up to 25 different alarm-reminders at 6 seconds each. So why not wake up to a recording of your kids saying, "Good morning, Mom!"? (Or maybe you don't want that.) We love how you can turn off the alarm by quickly pressing a button or just saying out loud, "Reminder Off." 
If you’ve never seen an alarm clock that can project the time onto the wall, you may be surprised at how handy this function can be. This Mesqool clock can project the time onto the ceiling, the curtains, or just about any other surface, thanks to the 180-degree swivel. So instead of squinting at the clock through sleepy eyes in the morning, you can just look up at the ceiling. The clock also includes AM/FM Radio, so you can listen to your favorite morning talk shows or follow along with your sports team while you get ready in the morning.
This SmartSet Alarm Radio with Bluetooth Speaker Desktop Clock is a thing of the past. The digital tuning clock radio automatically sets itself on the first use to the correct year, month, date, day, and time. The clock radio features Bluetooth v4.1 digital tuning FM radio. Includes a USB output for mobile charging (2.1a 5V) and a large and easy-to-read LED display. The alarm can be programmed to operate on weekdays only, weekends only, or all seven days of the week. Set the alarm to wake you...

The glossy finish reflects just enough light to show off the clock’s clean lines and rounded edges, and individuals who prefer a little bit of background ambiance throughout the night will enjoy the gentle ticking. The clock is also ultra-compact, so it won’t crowd your nightstand. The off button located on the top quickly silences the old-school beeping, too, but unfortunately, the device lacks a snooze button.

A well-made large wall clock that looks good and runs smoothly can bring charm and functionality to any space. For a fresh take on the traditional clock, consider this eye-catching design... Introducing Rimwood by Umbra Every Umbra wall clock is tested in our factory before shipping to ensure it works perfectly. This, coupled with a sleek and modern design, ensures you’re getting a clock that not only tells time accurately but also looks great. This classically-inspired clock has a truly...

Any expansion or contraction of the rod caused by changes of temperature will affect the timekeeping of a pendulum; e.g., a pendulum clock with a steel rod will lose one second a day for a rise in temperature of approximately 4 °F (2.2 °C). For accurate timekeeping, the length of the pendulum must be kept as nearly constant as possible. This may be done in several ways, some of which use the differing coefficients of expansion (the amount of expansion per degree change in temperature) of different metals to obtain a cancelling-out effect. In one popular compensation method, the bob consists of a glass or metal jar containing a suitable amount of mercury. The gridiron pendulum employs rods of different metal, usually brass and steel, while in the zinc-iron tube the pendulum rod is made of concentric tubes of zinc and iron. An improved method, however, is to make the pendulum rod from a special alloy called Invar. This material has such a small coefficient of expansion that small changes of temperature have a negligible effect and can easily be compensated for if required.
Add a dash of visual intrigue and stylish sophistication to your ensemble with this eye-catching wall clock, the perfect piece for your well-curated aesthetic. Hang it up on a deep blue or charcoal-toned wall in the living room to complement its shimmering silver finish and hard-lined metal design, then offset its striking starburst silhouette by arranging a console table below with glossy ceramic vases and simple metal picture frames. Curating a midcentury-modern aesthetic in your space? Lean...
Though no longer our first pick of timepiece thanks to the smart phone, this old-fashioned clock still scores points for form. Measuring 6.25'' H x 2.5'' W x 5'' D, this compact clock’s face is encased in a metal case with a brushed nickel finish and convex glass lens, while its faded dial stays in step with vintage styling. This item is battery operated, but does not emit a loud ticking noise, so you can snooze to your heart's content.
Categories: English 1-syllable wordsEnglish terms with IPA pronunciationEnglish terms with audio linksEnglish terms inherited from Middle EnglishEnglish terms derived from Middle EnglishEnglish terms derived from Middle DutchEnglish terms derived from Old Northern FrenchEnglish terms derived from Medieval LatinEnglish terms derived from Proto-CelticEnglish terms derived from Proto-Indo-EuropeanEnglish lemmasEnglish nounsEnglish countable nounsBritish EnglishEnglish terms with usage examplesen:Electronicsen:ComputingEnglish informal termsEnglish verbsEnglish transitive verbsEnglish slangNew Zealand EnglishRequests for quotation/Jonathan SwiftEnglish intransitive verbsEnglish dated termsWebster 1913English basic wordsen:Beetlesen:Cichorieae tribe plantsen:Clocksen:TimekeepingScots lemmasScots verbs
Set multiple alarms, but not on the same device. The world started relying on their smartphones to wake them up, and it simply doesn’t work. Nothing is better than a good old fashion alarm clock. Here’s the trick: any device in your home that has an alarm feature, set it. That means your stove in the other room, the microwave, your alarm clock, your smartphone, and perhaps a stereo system (if anyone’s still using those). It’s one surefire way to ensure that you’ll freak out all the way to your feet.

A clock that looks good and runs smoothly instantly adds charm and functionality to your living space. For a fresh take on the traditional wall clock, consider this eye-catching design. Introducing Ribbon Wall Clock by Umbra Add a modern, minimalist twist to telling time. With Ribbon, you get a stylish piece of wall décor and a functional wall clock all-in-one. Made with high-quality metal that’s been shaped to resemble overlapping ribbons, this unique clock features contrasting hands...
This Technology Curved Tabletop Clock and weather instrument offers curve-appeal. It also offers dynamic white LED display with a mirrored lens which can be seen from across the room and in darkened rooms. Features dual alarms with adjustable settings: HI/LO sound volume, programmable alarm days, snooze duration (5-60 mins), and auto-dim. Displays your current indoor temperature (F only) and humidity and can charge a mobile device with a bonus USB port in the back of the clock. Table standing...
Many alarm clocks have radio receivers that can be set to start playing at specified times, and are known as clock radios. Some alarm clocks can set multiple alarms, a useful feature for couples who have different waking up schedules. A progressive alarm clock, still new in the market, can have different alarms for different times (see Next-Generation Alarms) and even play music of your choice. Most modern televisions, mobile phones and digital watches have alarm clock functions to turn on or make sounds at a specific time.
This massive iron wall clock is 49" in diameter and is finished in off-white with an antique nickel outer ring that is moderately distressed and dented for an aged appearance. Black Roman numerals are centered on individual antique off-white panels. Quartz, battery-operated movement requires one AA sized battery. Some assembly is required. One year warranty and Free Shipping.
The Howard Miller Brohman 625-618 Large Wall Clock has a brushed, warm brown finish and metallic undertones. At 34" in diameter with a 22" aged dial this clock will fit just about any decor. With large Roman numerals and black hands this clock will be a favorite for years to come. Highly accurate quartz movement requires one AA battery (Not Included).

You don't have to use all of those features, however. You can set them in a variety of combinations, or even turn all of them off except for the flashing red lights. You can also set the length of the alarm's ring from one to 60 minutes, and choose a snooze option from one to 30 minutes. Plus, the clock has dual alarms, so both you and your partner can have different wake-up times.


Inspired by a vintage bicycle wheel, this awesome Oversized Kennan Metal 26.8" Wall Clock lends a touch of industrial chic style to your walls. This factory-chic timekeeper features rusted Arabic numerals, classic black spade hands on a battery-operated rusted gear movement, and gleaming metal wheel spoke accents. Create a factory-chic focal point in your dining room by mounting this piece on the wall over a reclaimed wood sideboard for guests to admire at your next dinner party or add it to...
Another type of analog clock is the sundial, which tracks the sun continuously, registering the time by the shadow position of its gnomon. Because the sun does not adjust to daylight saving time, users must add an hour during that time. Corrections must also be made for the equation of time, and for the difference between the longitudes of the sundial and of the central meridian of the time zone that is being used (i.e. 15 degrees east of the prime meridian for each hour that the time zone is ahead of GMT). Sundials use some or part of the 24 hour analog dial. There also exist clocks which use a digital display despite having an analog mechanism—these are commonly referred to as flip clocks. Alternative systems have been proposed. For example, the "Twelv" clock indicates the current hour using one of twelve colors, and indicates the minute by showing a proportion of a circular disk, similar to a moon phase.[74]

Designed to fit anywhere in your home, the Amazon Echo Spot uses voice recognition to let you see weather forecasts, read music lyrics, listen to Audible audiobooks, and more — and it’s all hands-free. Just ask Alexa to snooze the alarm. You can even ask Alexa to control the smart home devices in your house, including lights, locks, cameras, and thermostats. Need to make a phone call and don’t want to walk across the room to your phone? Ask the Spot to make phone calls or video calls to family and friends. As you can see, the Spot has much more in common with the Echo Dot than with a traditional alarm clock, although you’ll still get the time and a sleep mode. For more, read our full review.
The Howard Miller Brassworks II 625-569 is an over-sized, large wall clock showcases a distressed red dial with metal outer frame finished in antique black with brass undertones and highlights. The dial features aged iron-finished gears viewed through an open center. The spade hour and minute hands are finished in antique black with brass undertones and an antique black-finished gear in the center rotates. Quartz, battery-operated movement requires 1 AA battery. One year warranty and Free Shipping.

A clock radio is an alarm clock and radio receiver integrated in one device. The clock may turn on the radio at a designated time to wake the user, and may also include a buzzer. Typically, they are placed on the bedside stand. Some models offer dual alarm and "snooze", a large button on the top that stops the alarm and sets it to ring again a few minutes later.[18] Some clock radios also have a "sleep" timer, which turns the music from radio on for a set amount of time (usually around one hour). This is useful for people who like to fall asleep with the radio on.
The gorgeous combination of contemporary and modern accents results in the Bai Design 10" Gotham Designer Wall Clock. A simplistic design, the wall clock will exemplify the decor of your living room with its simple and subtle style. Add a dash of elegance to the walls of any room with this exquisite wall clock. Carved out plastic and glass, the wall clock follows the footsteps of modern architecture. The top and base materials are made out of a strong spray painted ABS bezel frame which...
More than just a time teller, oversized wall clocks create an eye-catching centerpiece in any ensemble while helping define your space’s aesthetic. Take this one for example: made from iron, it’s the perfect pick for any modern farmhouse-inspired decor. It strikes a circular silhouette and has an open and airy feel. Roman numeral accents line the periphery while two spade hands keep tabs on the time. It measures 30'' W x 30'' H x 1'' D and is operated by AA batteries.
Analog clocks usually use a clock face which indicates time using rotating pointers called "hands" on a fixed numbered dial or dials. The standard clock face, known universally throughout the world, has a short "hour hand" which indicates the hour on a circular dial of 12 hours, making two revolutions per day, and a longer "minute hand" which indicates the minutes in the current hour on the same dial, which is also divided into 60 minutes. It may also have a "second hand" which indicates the seconds in the current minute. The only other widely used clock face today is the 24 hour analog dial, because of the use of 24 hour time in military organizations and timetables. Before the modern clock face was standardized during the Industrial Revolution, many other face designs were used throughout the years, including dials divided into 6, 8, 10, and 24 hours. During the French Revolution the French government tried to introduce a 10-hour clock, as part of their decimal-based metric system of measurement, but it didn't catch on. An Italian 6 hour clock was developed in the 18th century, presumably to save power (a clock or watch striking 24 times uses more power).
"Love it...Love it....Just a basic alarm clock needed one to check that my FM transmitter is on the correct frequency one that had a digital tuner fits the bill just fine and a battery back up clock for time announcements ....What can I say, it's a quality alarm, that never fails, and is not expensive Not once has this alarm failed to wake me up, Digits are bright and easy to see If I were to say something negative, The time is a little too fast (in a month you'll notice your like a minute or two ahead of the actual time, easy fix though) And the radio connection needs to better"
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