How the score works
Each candidate meeting is checked against every participant’s working intervals, converted from their local hours on each date into exact instants. A person scores 0 when the whole meeting is inside their hours, and otherwise picks up a named penalty: partly outside, outside hours, night (22:00–07:00 local), plus an extra amount when it is not one of their working days.
Slots are ranked by the total, then by the worst single person’s penalty (so one person is not repeatedly sacrificed), then by the earliest time. You can change every weight. The score is arithmetic, not an objective “best time”: it does not know anyone’s preferences or local labour rules.
Why one week is not enough
Europe and North America change clocks on different weekends, so for a few weeks each spring and autumn the gap between London and New York is four hours instead of five. A slot that suits everyone in February can land outside someone’s hours in mid-March. The planner lists dates in your range where the same clock time scores differently.
Overnight shifts and breaks
Working hours like 22:00–06:00 run into the next day. Across a DST change such a shift can last 7 or 9 elapsed hours, and the planner uses the real instants. Breaks are removed from the working interval.