Shared Availability and Meeting Start Calculator
Intersect same-day participant availability and list grid-aligned start times that fit your meeting duration.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Merge overlapping intervals for each participant, intersect availability across every distinct participant, then retain grid-aligned starts whose full meeting duration fits inside the common interval.
First start=ceil(window start/grid)×grid; last start=floor((window end−duration)/grid)×grid
Worked example
Alice 09:00–12:00 and 13:00–17:00, Bob 10:00–16:00 and Cara 11:00–15:00 share 11:00–12:00 and 13:00–15:00. A 30-minute meeting on a 15-minute grid has 3+7=10 possible starts.
Assumptions and input details
All intervals use the same chosen day and clock basis; no dates, time zones or DST conversion are inferred. Identically spelled, case-sensitive participant labels represent the same person. Touching intervals for one person merge; a zero-length overlap between people is not availability. Overnight intervals must be split at midnight using 00:00 and 24:00 boundaries. Up to 100 intervals. No calendars are read and no meetings are booked.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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