Group availability finder: shared intervals and possible start ranges

Group availability finder: shared intervals and possible start ranges: purpose and instructions

Enter availability for 2–10 people on one Taipei date. Each person's overlapping, duplicate and touching intervals are merged before finding shared intervals and possible starts for a 1–1440 minute meeting. Calculation stays local; calendars are not read and data is not uploaded or saved automatically.

How to use

Choose a Taipei date and a whole-minute meeting length, then enter a unique identifier for each person. Give everyone at least one same-day availability interval or explicitly select no availability that day.
Enter whole-minute starts and ends for each person. Starts are limited to 00:00–23:59 and ends to 00:01–24:00. All people together may have up to 100 raw interval rows.
Calculate shared availability, review every full shared interval and its possible start range with both endpoints included, then copy the current result for human confirmation.

Frequently asked questions

What happens to one person's overlapping, duplicate or touching intervals?: The tool first merges one person's overlapping, contained, identical and touching intervals into maximum intervals, then intersects the interval sets for everyone. If intervals from different people only touch at an endpoint, their intersection has zero length and is not shared availability. Duplicate rows still count toward the 100-row raw input limit.
How do a full shared interval and a possible start range differ?: The full shared interval is the complete half-open interval [start, end) when everyone can attend. The possible start range contains the start times that still let the entire meeting fit after accounting for its length. Both endpoints are valid; if the interval exactly equals the meeting length, there is only one start time.
Is missing availability the same as selecting no availability that day?: No. Leaving availability blank without selecting the option means the data is incomplete and blocks the calculation. Explicitly selecting no availability that day is complete data and produces a valid result with no interval shared by everyone. A start cannot be 24:00; an end can use 24:00 for the end of the selected date. Overnight, second-precision and reversed intervals are rejected.
Are people and intervals sent to a calendar or saved?: No. Inputs and results are processed only in this page's browser memory. The tool does not read or connect to Google, Microsoft or Apple calendars, create events, send invitations, or write to the URL or persistent storage. Refreshing or leaving clears the data; you are responsible for copies you create.

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