where is the starting meridian for the longitude system
Prime meridian On Earth, starting at the North Pole and heading south to the South Pole, the IERS Reference Meridian (as of 2016) passes through:
Paris Peace Accords
Limit of a function (the Dirichlet function) has no limit at any x-coordinate.
Time Earth is split up into a number of time zones. Most time zones are exactly one hour apart, and by convention compute their local time as an offset from GMT. For example, time zones at sea are based on GMT. In many locations (but not at sea) these offsets vary twice yearly due to daylight saving time transitions.