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.
c. 1350–1400, Middle English clokke, clok, cloke, from Middle Dutch clocke (“bell, clock”), from Old Northern French cloque (“bell”), from Medieval Latin clocca, probably of Celtic origin, from Proto-Celtic *klokkos (“bell”) (compare Welsh cloch, Irish clog), from Proto-Indo-European *klēg-, *klōg-. Related to Old English clucge, Saterland Frisian Klokke (“bell; clock”), Low German Klock (“bell, clock”), German Glocke, Swedish klocka. Related to laugh.

While it’s not to be used in lieu of an alarm clock, this handy app will aggravate the hell out of you until you’re awake. You have to vigorously shake your phone for the duration of time previously set, or it’ll keep going. Pair this with sixty seconds after your new alarm clock going off, and you’ll throw yourself into a frenzy that you’ll need to power through to get out of. By that point, you’re already up.
Bring an earthy touch to your walls with this understated clock, a rustic accent for your space. Featuring a paneled distressed wood design with metal Roman numerals in a distressed gray finish, this clock brings a neutral touch to your look. Measuring at 27.5" x 27.5, this clock fits over any console or mantel space. Upkeep is easy—just wipe clean with a damp cloth—and install a AA battery (not included) to operate.
Scientific studies on sleep having shown that sleep stage at awakening is an important factor in amplifying sleep inertia. Alarm clocks involving sleep stage monitoring appeared on the market in 2005.[22] The alarm clocks use sensing technologies such as EEG electrodes and accelerometers to wake people from sleep.[23][24]Dawn simulators are another technology meant to mediate these effects.[25]
The invention of the mechanical clock in the 13th century initiated a change in timekeeping methods from continuous processes, such as the motion of the gnomon's shadow on a sundial or the flow of liquid in a water clock, to periodic oscillatory processes, such as the swing of a pendulum or the vibration of a quartz crystal,[3][63] which had the potential for more accuracy. All modern clocks use oscillation.

Transform an open and plain wall into a timeless focal point with this oversized clock, a versatile addition that lends any room in your home a touch of charm. Crafted of metal, this gray-finished piece features inner and outer rings connected by large Roman numerals that bring classic appeal to your space. This open-faced design is perfect for making a statement without overwhelming your arrangement. Mount this analog over a well-worn leather sofa so you don't lose track of the time as you...
The timekeeping part of all weight-driven clocks, including large tower clocks, is substantially the same. The figure shows the mechanism of a simple weight-driven timepiece with a pendulum. The frame is made up of two plates that carry the pivots of the various wheels and other moving parts and that are united and spaced by four pillars. The driving weight hangs from a line coiled around a barrel or sprocket, which is raised by turning the winding square or, in some cases, by pulling on the line. The main wheel engages with the centre pinion, on the arbor (axle) of which is also mounted the centre wheel. The front pivot of this wheel and pinion is lengthened to the right of the illustration; it carries the minute hand and part of the gearing necessary to drive the hour hand.
The pendulum is a reliable time measurer because, for small arcs, the time required for a complete swing (period) depends only on the length of the pendulum and is almost independent of the extent of the arc. The length of a pendulum with a period of one second is about 39 inches (990 mm), and an increase in length of 0.001 inch (0.025 mm) will make the clock lose about one second per day. Altering the length of a pendulum is therefore a sensitive means of regulation. The alteration is usually carried out by allowing the bob to rest upon a nut that can be screwed up or down the pendulum rod.

This dual tone wall clock features a handsome Rustic Cherry finish with a contrasting Vintage Umber inset panel. The wood stick moving pendulum features a spun brass-finished bob. Beneath a convex glass crystal, the dial features a two color wood-tone dial with gold Arabic numerals and aged brass-tone spade hands. Finished in distressed Rustic Cherry on select hardwoods and veneers. Quartz, non-chiming battery operated movement.

Reminisce fond memories of your school years with this 8.3" Retro Modern Wall Clock. Fashioned with contemporary and retro accents, the wall clock will transport you to your childhood days with its vintage design. Indulge in nostalgia with this simple and elegant wall clock. Crafted out of ABS thermoplastic and glass components, the wall clock is will elevate the vintage style of your home. The top and base materials are made out of sturdy ABS thermoplastic which gently wraps itself around the...
Marathon's Atomic alarm clock with temperature and date is packed with features. It has an ambient light sensor, which allows the auto-night light to illuminate the display when necessary. With a soft amber LED, the large digit display is easy to read at night and becomes even brighter if the Snooze/Light button is pressed. At a glance you can easily see the time, date, day and temperature. The controls on the front of the clock allow you to easily set the alarm, switch between Fahrenheit or...
Its display can be turned off or dimmed, so the large, easy-to-read numbers won’t blind you all night long. If you like to wake up to the radio or to an alarm that gets louder over time, you won’t find those features here (though there is a version with a Bluetooth speaker but still no radio). Still, it does its job well, and there’s a reason this clock is found in lots of hotel rooms.
"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"
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.
Set up your bedroom clock to be close enough to you to shut it off, but far enough away that you have to get up to actually his snooze or power it down. Your digital alarm clock should also be a radio alarm clock, so you can wake up to some tunes and start the day off right. Alarm clocks for heavy sleepers are going to have a louder radio capability, which will get through those thick dreams of yours, and get you up.

A well-made large wall clock that looks good and runs smoothly can add charm and functionality to any space. For a fresh take on the traditional clock, consider this eye-catching design... Introducing Madera Wall Clock by Umbra This beautiful, modern clock has a wood veneer dial, aluminum bezel, and glass lens. Inspired by modern wristwatches Madera is intended to serve as a finishing touch for any space. Featuring a silent sweeping quartz mechanism, this wall clocks battery operated design...
This fun desk clock from the popular Buddy family of products by Umbra holds the time aloft, grabbing attention and helping remind you of the importance of your time! Constructed of molded material with a soft-touch finish, the clock features a steel base for stability, bend-resistant clock hands, and an enclosed back. Operates on one AA battery (not included). Designed by Alan Wisniewski and Matt Davis for Umbra - the worldwide leader in innovative, casual, contemporary and affordable design...
In 1815, Francis Ronalds published the first electric clock powered by dry pile batteries.[48] Alexander Bain, Scottish clockmaker, patented the electric clock in 1840. The electric clock's mainspring is wound either with an electric motor or with an electromagnet and armature. In 1841, he first patented the electromagnetic pendulum. By the end of the nineteenth century, the advent of the dry cell battery made it feasible to use electric power in clocks. Spring or weight driven clocks that use electricity, either alternating current (AC) or direct current (DC), to rewind the spring or raise the weight of a mechanical clock would be classified as an electromechanical clock. This classification would also apply to clocks that employ an electrical impulse to propel the pendulum. In electromechanical clocks the electricity serves no time keeping function. These types of clocks were made as individual timepieces but more commonly used in synchronized time installations in schools, businesses, factories, railroads and government facilities as a master clock and slave clocks.

Stay on schedule and charge a range of devices with this innovative iHome dual-alarm clock. Place your compatible smartphone on top of the Qi-certified device for swift wireless charging, or plug your phone into the clock’s handy powered USB port. This iHome dual-alarm clock incorporates NFC technology, so you can connect an array of Bluetooth-enabled devices with a quick touch.

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).
A brushed and polished brass finish gives this metal carriage alarm clock its enduring style. The decorative handle, turned brass button feet, and polished brass-tone columns at the corners add to the clock's stately presence. Beneath a glass crystal, the brushed brass-tone dial features circular, diamond-cut numeral ring, black Roman numerals, black hour and minute hands, and brass second and alarm hands.

"Stripe Clock" is a modern metallic design created by the artist, Belle. Measured at 24 inches on each side, this metal art is made from a single sheet of metal expertly grinded and tinted and made in to a functional clock. It is mainly characterized by the bright stripe in the middle of the sheet of metal. Each stroke and grind pattern on this piece accentuates the beauty of the plain sheet of metal. The glimmer coming from the shallow grinds are like street lights illuminating the city in the...
This Roman Numerals Vintage Wall Clock makes telling time easier on the eyes. The clock’s backing is made to look like aged barnwood. It has black metal framing and large Roman Numerals on its dial cut from the same black painted metal. Silver studs dot the frame wherever the numerals join it for a striking, yet simple, accent. The hands of the clock are metal too, telling the time with a minute and hour hand. This stunning Roman Numerals Vintage Wall Clock really strikes a chord for home...
Health chose the Sonic Bomb as one of the best alarm clocks for heavy sleepers, commenting that the flashing lights, loud sound, and bed shaker should "deliver the full sensory message that grave danger awaits unless you get out of bed." Reviews.com likes it as well, although they aren't crazy about the appearance of the clock, claiming it looks like a gag gift. Still, they say, "It won us over with how effective and customizable it is."
Most digital clocks use electronic mechanisms and LCD, LED, or VFD displays; many other display technologies are used as well (cathode ray tubes, nixie tubes, etc.). After a reset, battery change or power failure, these clocks without a backup battery or capacitor either start counting from 12:00, or stay at 12:00, often with blinking digits indicating that the time needs to be set. Some newer clocks will reset themselves based on radio or Internet time servers that are tuned to national atomic clocks. Since the advent of digital clocks in the 1960s, the use of analog clocks has declined significantly.

An on-trend take on a retro design, this 12" round wall clock brings a splash of color to any space in your home. This budget-friendly accent showcases a circular face bordered by alternating blocks of green, blue, and red hues with black Roman numerals in the center. Its plastic frame ensures that it’s lightweight and easy to hang, while its metallic pierced hands offer subtle shimmer. This piece does not include batteries.


Need a little extra incentive to pry yourself out of bed? You'll have plenty of it with this no-nonsense wheeled alarm clock. After the first time you press snooze, this unit automatically starts moving away from you, creating enough distance to literally force you out of bed in order to shut it off for good. Plus, it also comes in pastel blue, white, red, and more.
The right wall-mounted timepiece can be and stylish accent or the focal point of your room's decor. Wall clocks offer an opportunity to reinforce the design of your space, enhance wall décor and add functionality to your room. Showcase them alone or make the clock a stylish addition to a gallery wall. Some designs even allow you to display multiple time zones.
This 33" metal wall clock features an antique nickel-finished frame is 7" wide and curves down from the face to the wall hiding the almost 3" in depth. The frame also features 100 decorative nail heads in two rows one on the inside of the frame and one on the outside of the frame.The accurate Quartz movement is operated by one AA battery. One year warranty and Free Shipping.
Certainly not just for telling time, wall clocks are perfect for adding artful appeal to your kitchen wall or acting as a focal point above the living room mantel. Take this one for example: crafted from metal, its frame features an openwork design and a black finish for a look that fits right into traditional abodes and modern farmhouses alike. Measures about 30'' in diameter. Requires one AA battery to operate.
Fortunately, Ruggie takes the ease and convenience out of simply rolling over and slapping “snooze.” With Ruggie, you must apply pressure to a plush mat for three seconds to stop the alarm. The alarm can be set to 120 decibels, too, to further annoy you out of bed. For sake of perspective, 120 decibels is on par with the noise level of a chainsaw. Pleasant.
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.
Time switches can be used to turn on anything that will awaken a sleeper, and can therefore be used as alarms. Lights, bells, and radio and TV sets can easily be used.[32] More elaborate devices have also been used, such as machines that automatically prepare tea or coffee. A sound is produced when the drink is ready, so the sleeper awakes to find the freshly brewed drink waiting.[33]
To see if ShippingPass is right for you, try a 30-day free trial. Also, with ShippingPass, there is no need to worry about commitment. If you decide you want to discontinue the service, you can cancel your subscription at any time. No matter what your shipping needs, Walmart's got you covered. Sign up for ShippingPass so you can shop more, save money and live better.
×