- The time determined according to the longitude of a place is the local time of that place
- All places on the same meridian will have the same local time
- The local time of a place can be calculated by knowing its longitude and the local time and longitude of another place
- For example, if the local time at Greenwich (0° longitude) is 12 noon, then the local time at a place located at 60° E longitude will be 4 p.m. and the local time at a place located at 60° W longitude will be 8 a.m.