CHILEAN NAVY HYDROGRAPHIC AND OCEANOGRAPHIC SERVICE

FREQUENTLY ASKED QUESTIONS (FAQs)

1.Question: ¿ How can I synchronize my computer if I have a Unix/Linux OS?


Answer: normally, this OS is totally compatible with the use of the NTP protocol, therefore, only the most representative cases will be shown. From the console, using the command line the NTP services must be started following these steps:


1. Edit the file: /etc/ntp.conf and add the line: server ntp.shoa.cl

2. Test the connection using the command: ntpdate ntp.shoa.cl this will result in the time synchronization with the server 01 May 10:52:29 ntpdate[16699]: step time server ntp.shoa.ck offset -3.456078 sec


From the graphic interface: enable the service from the time and date window, adding as a server ntp.shoa.cl and activating the ntp service (select Use ntp server)



2. Question: when I tried to synchronize my personal computer through the AboutTime program, a message reads: “time out waiting for ntp.shoa.cl” what do I do?


Answer: Generally, this problem appears when users are connected to a local area network (LAN) behind the firewall. It is always convenient to first check that there are no local connectivity problems. Once this has been checked and discarded, contact your network administrator to check the safety rules of your firewall, which eventually might restrict traffic on the port 123, which is used by the NTP protocol (Network Time Protocol). It is important that you know that if you use a LAN, your PC, preferably, has to be synchronized to the time of the server, with which it is authenticated as a network user. Therefore, the server must synchronize its clock with the correct time to maintain convergence of all the networking media and devices connected to the network.




3. Question: Where can I find information about the functioning of the NTP protocol?


Answer: Visiting the website http://www.ntp.org


4. Question: Is the word “Huso” (Time Zone) written with an H in Spanish?


Anwer: Yes. In relation to the use of the letter “H” in the word Huso, in the context of the concept of “Time Zone”, according to RAE http://www.rae.es http://www.rae.es the definition is as it follows: “1. M. Geogr. Each part of the surface of the Earth divided into 24 equal meridians in which usually applies the same time.”


5. Question: What is UTC time?


Answer: Coordinated Universal Time (UTC) follows the TAI in an exact way, except for a difference of exactly 32 seconds. These leap seconds are on the report of the International Earth Rotation and Reference Systems Service (IERS) to ensure that, in general with the passing of the years, the sun superimposes itself in 0.9 seconds of the 12:00 UTC at the Greenwich Meridian. Therefore, the UTC is the modern successor of the Greenwich Mean Time, GMT, which was used when the unit of time was the mean solar day.


The International Atomic Time (TAI) is calculated by the BIPM, using the readings of more than 200 atomic clocks located at the meteorological institutes and observatories in more than 30 countries around the world. The TAI is available every month on the circular T of the BIPM. It is estimated that the TAI cannot lose nor win regarding an imaginary perfect clock for over a tenth of microsecond (0,0000001) per year.


More information on: http://www.bipm.fr/en/scientific/tai/time_server.html

6. Question: who determines the begging of the summer time or winter time in Chile?


The Government determines the dates for these transitions, through the Ministry of Internal Affairs and Public Security.


Technical considerations and recommendations for the daylight saving time

According to the Supreme Decree n° 153 of February 6, 2013, of the Ministry of Internal Affairs and Public Security which extends the Summer time until April 27 2013, and resuming the validity of the time change on the first Saturday of the month of September at 24:00 hours:

- Operating systems that have not been patched or updated to be used on the America/Santiago time zone and that have been programed to automatically perform the time change for the second Saturday in October should remain on the GMT/UTC -04 time zone only until September 7 at 24:00 hours. Starting September 8 at 00:00 hours they have to switch time zones to GMT/UTC-03.

- Subsequently, using GMT/UTC -03 synchronize with ntp.shoa.cl for perfect accuracy.

If you are not doing this manually, when you perform the synchronization with our server note that:

- The time server ntp.shoa.cl is based on UTC.

- The server ntp.shoa.cl through the NTP protocol will execute the time corrections based on the time zone set on your computer.

- The NTP protocol does not modify the time zones of the clients.


Note:

For Microsoft systems visit http://www.microsoft.com/chile/cambiodehora/default.aspx

for specific problems and/or other specific consequences of the operating systems related to this time zone change, contact your product manufacturer./p>