Add two or three cities and see the fairest hour for a recurring call — the one that spreads the early starts and late nights, not just the one that suits the West.
Two-city time is easy; a three-city recurring meeting is the hard part — no single hour sits inside everyone’s working day, so someone takes an early start or a late night. This planner finds the fairest slot (spreading that cost) and the most efficient one (least total), and shows on a live day/night map exactly who sacrifices. Start from a corridor below or type your own cities.
Each city’s core day is 9:00–17:00 (zero cost). Outside it, an hour later hurts less than an hour earlier — staying online past five beats waking before eight — so the penalty curve is asymmetric. Fair minimises the worst-off city first (leximin); Efficient minimises the total. Both land on the working-hours frontier — Fair just refuses to let one city absorb the whole gap.