Interval of Time, Interval of Space
There's a gate that the sun goes through at a regular interval. There is an interval of time in the sense that the sun goes through it at the same time every day. And there is an interval of space in the sense that it has to go through the space between the gate posts.
This method of keeping track of intervals of time was invented by the great Khans of Mongolia, specifically the most famous Khan of all: Genghis Khan (かん).
Genghis Khan has had a huge impact on the world as we know it, especially the Eurasian continent of the past, so he's going to come up a lot from now on. Be prepared to get very familiar with him and his friends!