A shift of travel is a one month stay in any given location. One month is around the amount of time that it takes to start to get to know any place in the world, and this is an appropriate amount of time by which to measure phases of world travel. In usage, a traveler can say, “I was there for a shift,” or “I plan to spend three shifts here,” to express the degree by which they intend to experience a place.
For more on what constitutes the philosophy behind traveling in shifts, go to How to Fully Enjoy Traveling.