A lot of devices these days have a clock built into them like mobile phones, desk phones, microwaves, televisions, digital video recorders, computers as well as in our cars. With all of these clocks, which one is the most accurate and how can you ensure that your time is kept in sync with the rest of the planet (without throwing daylight saving into the mix)?
Time synchronisation has been around for a while and the most popular way for this to take place is via the Network Time Protocol (or NTP for short). Businesses use NTP to keep all the time in sync across all of their servers but also recent desktop operating systems including Windows 2000 and later, MacOS X and all recent versions of Linux have built-in support for time syncing. I won’t go too far into the mechanics of NTP or clock strata at this stage suffice to say that it is an interesting piece of technology.
Desktop Voice over IP (VoIP) phones such as the Cisco IP Phones will get their time from the Cisco Call Manager on the network or, it its absence, the TFTP server on the network from which it downloads its configuration files.
All of the major smartphones will also synchronise their time against your computer to help ensure uniform time keeping. Also, a range of phones support the Network Identity and Time Zone (NITZ) protocol, including:
- Apple iPhone,
- Blackberry phones,
- HTC phones,
- Nokia phones.
NITZ allows a phone to receive local time, date and time zone information over a GSM compatible network and serves as an alternate means by which to keep the time on your phone in sync.
As for other devices like microwaves and televisions, the clocks in these devices (most likely cheaper models) may rely upon two things, specifically:
- time being accurately entered into the device in the first instance,
- the frequency of the supplied electricity;
- a higher frequency will result in a faster click whilst a slower frequency results in a slower clock.
So if you are keen to keep good time, your computer and your mobile phone would probably be best placed to help you out. Certainly, your computer will do the best job of automatically looking after daylight saving for you followed by more recent mobile phones (particularly smartphones).