Cities located on the same meridian must have the same what

ANSWER:

The cities that are located on the same meridian must have the same time.

EXPLANATION:

Meridian is the imaginary circle that divides the earth in two half. The main characteristic of this imaginary line is that, it defines the position and time zone of any country. Time for every country is determined by the meridian. So, if two countries lie on the same meridian then they must have the same time zone.  The reason for the same country to have difference in time is also due to the meridian line.