The fairest hour for a recurring call across your cities — drag the marker to test any slot.
Day & night at the selected time☀ in daylight · ☾ after hours
Recommended slot
—
Every half-hour, coloured by how much it costs each city
—
in hoursedge of dayearly / latea real askasleep
How “cost” is scored
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.