[:fr]
Time zones are areas of the Earth that have the same conventional time.
Before time zones were adopted, people used to use local solar time (mean or true) in the various areas of the Earth, which produced a time slightly different from place to place. Time zones partially rectified the problem by setting clocks of a region on the mean solar time of the central meridian of the zone to which the area belongs.

 

 

[:es]
Time zones are areas of the Earth that have the same conventional time.
Before time zones were adopted, people used to use local solar time (mean or true) in the various areas of the Earth, which produced a time slightly different from place to place. Time zones partially rectified the problem by setting clocks of a region on the mean solar time of the central meridian of the zone to which the area belongs.

 

 

[:]