What counts as a valid meeting window?
A person counts as available only when one of their intervals covers the entire requested meeting. A 60-minute meeting therefore does not count someone who is free for only the first 45 minutes. Overlapping or touching intervals for the same person are merged first.
Maximum attendance, not just common free time
Requiring everyone can produce no result even when there are several useful times. Set a minimum attendance to find windows with the highest number of people first. The result lists who is available and who is missing for each candidate, so the trade-off is visible.
Why candidate starts are not brute-forced minute by minute
The best attendance can only change at the start or end boundary of someone's availability. The solver therefore evaluates mathematically relevant boundary starts (including an interval end minus the requested duration) instead of scanning every minute. That keeps large schedules fast without changing the optimum under the interval model.
Calendar export
Download the best slot as a standard .ics event. The file stores the selected instant in UTC so calendar apps can display it correctly in their own timezone. No calendar account is connected and nothing is sent to an external scheduling service.
Is my data uploaded?
No. The availability is merged in your browser, so nothing you add is sent to gratistools.be. See the privacy page for details.