A plurality of slave clocks are controlled and synchronised from a central station which transmits to each slave clock frequent coded signals each of which conveys in coded form complete information as to the time, and possibly also the date, to be displayed by each slave clock.
A clock adjusting method and an electronic equipment using the method are disclosed in which a clock portion of an electronic equipment is correctly and simply adjusted by use of time information in broadcasting waves. In the case where a time indicated by the clock portion of the electronic equipment is "0:00" a.m. or after "0:00" and before "23:00", the time of the clock portion is set at a reference time based on the time information. In the other case, the judgement is made of whether the time of the clock portion indicates a time of the next day as compared with the reference time or a time of the preceding day as compared with the reference time. When the time of the clock portion indicates a time of the next day as compared with the reference time, the time of the clock portion is set at the reference time while a day of the week indicated by the clock portion is put back one day. When the time of the clock portion indicates a time of the preceding day as compared with the reference time, the time of the clock portion is set at the reference time while the day of the week of the clock portion is put forward one day.
An electronic timepiece comprises a reference oscillator, a counter for counting reference clock signals from the reference oscillator to obtain a time count signal, and a display device for displaying a time count value of the counter, in which there is provided an input terminal detachably connected to an external data supply device to permit a preset initial count value data to be inputted from the outside. A master device for the timepiece includes an output terminal detachably connected to the input terminal of the timepiece. The preset initial count value data is supplied to the counter of the timepiece through the output terminal which is detachably connected to the input terminal of the timepiece.
A driving mechanism is arranged in a hand for relatively rotating the hand in relation to a shaft which supports the hand, and clocking is thereby performed.
A time measuring method is combined with an automatic rate correction process in a digital or quasianalog clock; a clock rate deviation is repeatedly measured, in a predetermined lock-in-range, derived from the clock oscillator frequency, by means of a time mark received from a transmitter; the deviation data are stored and used for correcting the clock rate and the oscillator frequency whereby the stored data are maintained until the arrival of the next time mark.
To set the initial time in a clock managed by an operating system in a personal computer system, when the power is turned on, the ROM-BIOS of the personal computer system is checked and the operating system is booted. Next, the current time is read from a CMOS clock of the personal computer system and the time read is set as the initial time in a clock managed by the operating system. Then, the current time is read from the CMOS clock again and the read current time is compared with the time of the clock managed by the operating system. If the times do not match each other, the above reading and setting processes are repeated. Thus, the time managed by the CMOS clock and the time managed by the OS clock in a PC system can coincide so that the time managed by the OS clock can be reliable for application programs requiring an accurate real-time management.
