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.

Alarm clocks, like almost all other consumer goods in the United States, ceased production in the spring of 1942, as the factories which made them were converted over to war work during World War II, but they were one of the first consumer items to resume manufacture for civilian use, in November 1944.[13][14] By that time, a critical shortage of alarm clocks had developed due to older clocks wearing out or breaking down. Workers were late for, or missed completely, their scheduled shifts in jobs critical to the war effort.[14] In a pooling arrangement overseen by the Office of Price Administration, several clock companies were allowed to start producing new clocks, some of which were continuations of pre-war designs, and some of which were new designs, thus becoming among the first "postwar" consumer goods to be made, before the war had even ended.[15][16] The price of these "emergency" clocks was, however, still strictly regulated by the Office of Price Administration.[14]
The origin of the all-mechanical escapement clock is unknown; the first such devices may have been invented and used in monasteries to toll a bell that called the monks to prayers. The first mechanical clocks to which clear references exist were large, weight-driven machines fitted into towers and known today as turret clocks. These early devices struck only the hours and did not have hands or a dial.
This Mission style wall clock is finished in a Mission Oak dark finish. A parchment dial features dark brown numerals and hands. Decorative, wooden moldings frame the dial. Circular brushed brass swinging pendulum is antiqued and framed with wooden, reeded grilles. Quartz, dual chime movement plays Westminster or Ave Maria chimes, and features volume control and automatic nighttime shut-off option. Shadow collection - matching floor clock available. Size: H. 32-1/2" W.16-3/4" D.6"

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...
Most digital computers depend on an internal signal at constant frequency to synchronize processing; this is referred to as a clock signal. (A few research projects are developing CPUs based on asynchronous circuits.) Some equipment, including computers, also maintains time and date for use as required; this is referred to as time-of-day clock, and is distinct from the system clock signal, although possibly based on counting its cycles.
Get up one minute earlier each and every day. We have biological clocks; it’s not just some weird term we use. Time doesn’t exist. I’m not going to get all existential on you and make you contemplate your place in the universe, because you already know what that is—being the version of you that gets up earlier. Your body needs time to adjust, and if you can wean into it like this, in a month, you’ll be waking up a half-hour early.

A: If your clock is waking you up too abruptly, pulling you out of REM sleep like Leo from a dream inside another dream, your body goes into a moderate level of shock. You’ll feel your heart kick up all of a sudden, because now you’re awake, and your body has been taken by surprise. You have to go from a resting heart rate of 40-50 BPM, back to a standard heart rate (or a little higher at first) of around 60-100 BPM


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.
Slave clocks, used in large institutions and schools from the 1860s to the 1970s, kept time with a pendulum, but were wired to a master clock in the building, and periodically received a signal to synchronize them with the master, often on the hour.[71] Later versions without pendulums were triggered by a pulse from the master clock and certain sequences used to force rapid synchronization following a power failure.
“Love how simple this digital timer is. I travel a lot, and it’s small enough to put in my purse. The off button is convenient because it keeps the buttons from being pressed while stored away and conserves the battery, but when you turn it back on, your setting are stored so no need to reset [each] time. … [There’s just the] clock, alarm, snooze, on/off. The smaller and simpler the better when I’m traveling.”
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