Geography map skills: How time zones work, especially with regards to how time moves forward as the earth's position relative to the sun changes.
International Date line:    • International Date Line  
Latitude and Longitude Coordinates:    • Mapwork coordinates degrees, minutes ...  
Mapwork Tutorial Playlist:    • Geography mapwork / mapping  
UTC = Coordinated Universal Time: https://en.wikipedia.org/wiki/Coordin...
Interactive timezone map: https://www.timeanddate.com/time/map/
Three different calendar days at once (scroll down: https://en.wikipedia.org/wiki/Interna...)