How AutoWhenn decides what "best" means
A slot where everyone is technically free at 6:30am is not the same as a slot at 2pm. AutoWhenn knows the difference. Here's how it scores and ranks candidates to find the time that works best — not just the time that works.
The problem with "find an intersection"
The naive version of a scheduling algorithm is: find a time when everyone is free. That's the right starting point, but it's not the whole job.
A 6:30am slot on a Tuesday is not the same as a 2pm slot on a Thursday, even if both show as available in everyone's calendar. A technically valid intersection is not necessarily a humanly sensible one. Someone who is "free" at 6:30am may be free because they haven't blocked that time — not because they want a meeting there.
This is the problem AutoWhenn is built to solve. It doesn't just find times everyone is free. It ranks them.
How AutoWhenn scores slots
When all participants have shared their availability, AutoWhenn has a set of candidate slots — times that appear free across the group. It then scores each candidate against the preferred hours set by the meeting organiser.
The scoring logic minimises total inconvenience across participants. A slot that falls within preferred working hours for all participants scores highest. A slot that falls outside preferred hours for one participant scores lower. A slot that falls outside preferred hours for several participants scores lower still.
The slot with the highest combined score is the one AutoWhenn confirms.
The preferred hours setting
When you create a meeting in Whenn, the schedule step lets you set preferred hours. The default is working hours (9am–6pm). You can also choose mornings, afternoons, any time, or a custom range.
These hours tell AutoWhenn where to bias. They are not a hard constraint — if no slot exists within preferred hours for all participants, AutoWhenn will find the best available option outside them rather than failing to confirm. But in most cases, preferred hours are the primary filter that separates a good time from a technically valid but inconvenient one.
Timezone handling
AutoWhenn converts all participants' free/busy data to UTC for comparison. When it finds the best slot, it converts the confirmed time back to each participant's local timezone for the calendar invite.
The timezone handling also applies to preferred hours. If you set preferred hours to 09:00–17:00, that means 09:00–17:00 local time for each participant — not 09:00–17:00 UTC. A participant in Singapore and a participant in London each have their own local working hours, and AutoWhenn accounts for both when scoring slots. This is especially relevant for the cross-timezone meeting setting, where the challenge is finding an overlap that falls within reasonable hours for participants spread across multiple continents.
Avoid weekends
When you enable the avoid weekends option on the schedule step, AutoWhenn excludes Saturday and Sunday from consideration entirely. Slots that fall on weekends are not scored — they are removed from the candidate set before scoring begins.
The short answer
The best slot is the one with the highest combined availability score, weighted toward times that fall within preferred working hours for the most participants, in their local timezones, on the days you've allowed.
Read next
Whenn handles the entire coordination process — automatically.
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