Traveling between hexes in the world is not instant. Going from one tile to another takes 15 minutes, which means 375 minutes (6.25 hours) to travel from one end of a chunk to the other.
To illustrate, given a perfect path, it would take 125 hours to travel from any corner to any other corner (not counting the “my-chunk” bonus).
To encourage short trips, traversal within a chunk is half of the time it would normally be, as most players will spend time within their chunk more than anything else.
If a player owns villages in both chunks, the “current” chunk refers to the chunk the village that executed the traveling order is from.