How to synchronize time about the Internet

How to synchronize time about the Internet

Atomic clock - expensive and bulky device. It is much more convenient to receive signals of the exact time by phone, radio or from the satellite. For quite some time now the Internet became one more channel for obtaining information on the exact time.


1. If you want to obtain only from the Internet information on the exact time, and to carry out synchronization manually, use services of one of so-called Daytime-servers. Before being connected to such server, make sure that you have a console Telnet-client (it meets both in Linux, and in many versions of Windows). Start the telnet program with the parameter consisting of the IP address of the server and the port number separated by a colon. The port number for the Daytime protocol - always 13. For example: telnet
In reply you obtain information on time and date then it will automatically be disconnected. Do not pay attention for hours - the server is in other time zone. You need information only on minutes and seconds. Use only those servers from the list about which it is directly told that they support the Daytime protocol. Never be connected to the same server more often than time in four seconds inclusive, differently your IP address will be blocked (your requests will be taken for the DoS-attack).

2. To synchronize watch of the computer with the server automatically, it is necessary to use other protocol - NTP. He is supported by all servers from the specified list, even those which do not work under the Daytime protocol. However it is the best of all to use for this purpose more exact NTP server - The public pool of the servers is a little less exact. Pay attention that URL of these servers without the usual line ""http://www"" are written. Requests to any NTP servers cannot also be repeated at all more often than time in four seconds inclusive.

3. Automatically to synchronize the built-in watch of the computer with the NTP server in the Linux operating system, install a ntp package in the beginning. Then enter a command: sudo ntpdate (URL NTP server)

4. That in the Windows operating system time was automatically synchronized with the NTP server at each turning on of the computer, select the Date and time item in "Control panel". Switch to the Time of the Internet tab. Install the Include Synchronization with the Time Server on the Internet check mark. Enter in the only thing on the page the URL field of the NTP server.

5. Install Server Time J2ME-application on the mobile phone. Having started it, enter in the URL settings of the NTP server. Then select the item "Start!" in the menu. After the request is made, you will be able to compare time on the server to time in the built-in hours of phone. It is necessary to carry out synchronization manually, despite use of the NTP protocol. It is connected with the fact that the Java virtual machine on the phone does not allow applications to change indications of system hours.

Author: «MirrorInfo» Dream Team