The most accurate clocks are atomic. But they are bulky, expensive and consume a lot of electricity. Therefore, organizations that own atomic clocks provide information about the current time in various ways to those who do not have such a clock.
Find out the phone number of the exact time in your city. Call him. If you use an unlimited tariff, the call will be free, and if not, its cost will be the same as a regular call to a landline number. After the voice information, a short beep will sound - its beginning will correspond to the time announced by the voice.
At the end of the hour, turn on the receiver tuned to the Radio of Russia radio station, or the subscriber loudspeaker (radio point). If you are using a three-way speaker, select the first program. At the same time, remove the battery from a conventional mechanical alarm clock exactly at the moment when the second hand shows zero seconds. Set the minute hand to zero minutes so that the hour hand points exactly to the next hour. Wait for the exact time signals, and as soon as the last one (sixth) sounds, quickly replace the battery.
Residents of the European part of Russia can receive coded time signals transmitted from Germany. To do this, buy a watch with a built-in DCF77 receiver at auction. Due to poor reception, they will be synchronized only at night. They will be automatically rearranged to the German time zone, so do not pay attention to the hour counter. And according to the minutes and seconds counters, manually set the rest of the hours in the house.
With a GPS receiver that supports the NMEA standard, you can get accurate time information from anywhere in the world. Connect the receiver to a COM or USB port of the computer, start the terminal emulator, select the appropriate port and baud rate equal to 4800, the number of bits equal to 8, disable parity and enable one stop bit. Find a line in the data stream that begins with "$ GPZDA" (without quotes) and read the current time in it. Again, ignore the watch - it may be in a different time zone. But the data on minutes and seconds will be very accurate.
For example, in the line "$ GPZDA, 152034.00, 10, 3, 2011,, * 57" (without quotes), the number 152034 means 15 hours, 20 minutes and 34 seconds.
Go to the following site:
Connect to any of the servers listed there using the Telnet protocol, be sure to use port 13, for example, telnet nist1-chi.ustiming.org:13.
In response, you will receive information about the exact time in any form, for example, 55970 12-02-13 19:48:21 00 0 0 406.5 UTC (NIST) *. In this case, the time zone will also be different, but the data on minutes and seconds will be accurate. Do not make requests to the server more than once every four seconds - this will be mistaken for an attack.