Ask AI who's free from a rota without inventing cover
A blank cell is not a colleague volunteering. Ask AI who's free from the rota you have, not the cover you wish you had.
Example output
Who's free at 11:00, with blanks kept as unknown
Fictional rota: A's overlapping entries count once, B's blank stays unknown, and C's shift ends as the slot starts.
| Supplied record | Interval / state |
|---|---|
| A | 09:00–11:00 and 10:00–12:00; overlap counts once |
| B | Unknown; not observed free time |
| C | 09:00–11:00; end-exclusive |
Read the prompt
Create a local availability view from this permitted interval file.
Preserve anonymous IDs, source dates, named zones and interval states.
Show unknown separately from available and unavailable.
Display overlaps for the same ID without double-counting them.
Use [start-inclusive, end-exclusive] boundaries as specified in the source.
Keep source intervals inspectable. Do not infer skills, productivity,
health, staffing recommendations or total capacity from this display.
Return the actual local files and an explained source-to-lane mapping.What you'll make
a checked answer to “who’s free then?” from a spreadsheet rota, with each person marked available, not available or unknown, and, if your team needs one, a simple shared availability view.
What you'll need
the rota, using initials or staff IDs rather than names if you can, and your work AI account (ChatGPT, Claude, Copilot or Gemini). Removing names doesn’t make a rota fine to share, so use only what your organisation allows in that account. About 10 minutes. If availability lives in shared calendars rather than a spreadsheet, your calendar’s own scheduling view is the quicker route.
1. Ask who’s free, and say what a blank means
Upload the rota or paste the relevant rows. Ask about one specific time slot, and tell the AI how to read the sheet: a blank means nobody has said, not that the person is free.
Using this rota, who is available on [day] from [start] to [end]?
Treat a blank cell as unknown, not available, and list unknowns separately.
A shift ending at [start] means that person is not available for this slot.
If one person has overlapping entries, combine them; don't count them twice.
For each person, quote the rota entries you used.[day], [start] and [end] are the slot you’re filling, such as “Tuesday”, “11:00” and “12:00”.
Why this works: the three rules cover the three ways a rota answer goes wrong, and quoting the entries lets you check each person in seconds.
What you should see: three short lists, available, not available and unknown, each with the rota entries behind it.
2. Check two people against the sheet
Pick two people from the answer, ideally one marked available and one marked unknown, and find their rows in the rota yourself. Then look for the three awkward cases: someone with overlapping entries, someone with a blank, and someone whose shift ends exactly when the slot starts.
Why this works: if two people check out and the awkward cases are handled, the rules in the prompt worked. If one doesn’t, you’ve found the problem before anyone is booked.
What you should see: every person’s status matching the rota entries quoted for them.
3. Ask for a shared view if the team needs one
If several people check the rota every week, a simple view helps more than a chat answer. Ask for a single HTML file or a formatted sheet, then check it with the same awkward cases.
Make a simple availability view from this rota: one row per person, one column per hour.
Use three states with words as well as colours: available, not available, unknown (blank in the rota).
Combine overlapping entries for the same person without double-counting.
Don't add totals, rankings or suggestions about who should do what.Why this works: words as well as colours keep the view readable for everyone, and “no suggestions” keeps the decision with you.
What you should see: a grid where blanks show as “unknown”, not as free.
Check the result
- Every blank in the rota shows as unknown, never as available.
- Someone whose shift ends at 11:00 isn’t listed as free for an 11:00 slot.
- Overlapping entries for one person add up to their real span, not the sum of both entries.
- Each status matches the rota entries quoted for that person.
The usual failure: the AI reads a blank as free. It’s an easy mistake, because a blank looks like “nothing booked”. Spot it by finding anyone listed as available whose rota entry for that slot is empty.
You've listed [person] as available from [start] to [end], but their rota cell for that time is blank.
Mark them as unknown, move them to the unknown list, and recheck everyone else for the same mistake.Worked example: finding cover for 11:00 on Tuesday
Fictional example. A team lead needs one person for an 11:00–12:00 client call on Tuesday and asks AI who’s free.
A available 09:00–11:00
A available 10:00–12:00
B (blank) 10:00–12:00
C available 09:00–11:00First answer (wrong): “A, B and C are free. A has four hours available on Tuesday.”
Repair: the repair prompt above for B, then the step 1 rule about shifts ending at the start of the slot for C.
Repaired answer: “Available: A (09:00–12:00, from both entries). Not available: C (shift ends at 11:00). Unknown: B (blank from 10:00 to 12:00, ask B).”
- B was the risky one. A blank turned into a booking would have put a colleague on a client call they’d never agreed to.
- A’s two entries overlap from 10:00 to 11:00. Combined, that’s 09:00–12:00: three hours, not four.
- C’s shift ends exactly when the call starts. “Available until 11:00” means not available at 11:00.
Task kit for this job: Download (ZIP) · Reusable instructions
Go deeper
Keep dates and time zones with the rota
If the team spans offices, a rota time needs its date and place. 11:00 in one office can be a different hour, or a different day, somewhere else. The time-zone guide shows how to check this around clock changes.
Make the legend readable for everyone
Use words or patterns as well as colour for unknown and not available, and check the view on a phone before you share it. A grid that only works in green and red leaves some colleagues guessing.
Availability isn't an assignment
A free slot doesn’t tell you about skills, workload or who’s allowed to take the work. Use the view to see who could be asked, then make the decision with the people and policy involved. Don’t ask the AI to choose who should do it.