Bookings with me buffers and start-time increments

What you can set on a meeting type#

Microsoft documents these per meeting type:

• name
• colour category and description
• online or in-person
• duration
• public or private
• schedule, either regular Outlook hours or custom hours per weekday
• Buffers, before and after
• Minimum Lead Time and Maximum Lead Time
• email reminders and follow-ups under Advanced Settings

There's no start-time increment in the Microsoft Learn article. Users describe a limited interval choice instead. A 2024 user switched between 20-minute and 15-minute intervals, and a 2026 user found "30 minutes or 1 hour" and no 45. When the meeting type sets no interval, the page code uses 30 minutes.

Why the starts land where they do#

What we saw when testing (September 2026)#

We captured live Bookings with me pages and the calls they make, and reproduced every slot they showed. Personal pages place start times differently from shared pages:

1. The server sends back your free blocks, with work hours or custom hours and busy time already applied.
2. The page walks each block on a grid of the interval counted from local midnight. A 45-minute interval is the exception: it walks a 15-minute grid.
3. The before-buffer is added to every grid point.
4. A start is kept only if the meeting ends no later than the end of the block minus the after-buffer.

Our live personal captures used 30-minute meeting types with no buffers, so steps 3 and 4 come from the page code rather than a live capture. But both Q&A reports below match them to the minute.

To get rid of the "5-minute buffer", either choose an interval whose grid includes the start of your hours, or start your hours on a grid point (17:00 or 17:20 for a 20-minute grid).

A gap after each meeting#

Use the after buffer, not the before buffer. The after-buffer leaves starts on :00 and :30, but it doesn't guarantee a gap. Whether an 11:00 booking with a 10-minute after-buffer stops someone taking 11:30 depends on how the service counts buffer time around existing personal bookings. Microsoft doesn't document that for Bookings with me, and we haven't tested it. So set the buffer, make a test booking, and check whether the next slot disappears.

There are two ways to guarantee a gap on a personal page:

• A 60-minute interval for 30-minute meetings. You always get at least 30 minutes between bookings, at the cost of half your slots.
• A longer duration. A 40-minute meeting type blocks 40 minutes, but the booker's invitation also says 40 minutes.

45-minute starts#

A personal page can't give you 10:00, 10:45, 11:30. Even with a 45-minute interval, it offers every quarter-hour. A moderator suggested splitting your custom hours into back-to-back windows (10:00–10:45, 10:45–11:30 and so on). With a 30-minute interval that fails, because a window starting at 10:45 has no grid point at 10:45. With a 15-minute grid it depends on whether the server returns adjacent windows as separate blocks, which we haven't tested. Check the public link before relying on it.

The workaround: a single-staff shared booking page#

A shared booking page with you as the only staff member has what personal pages lack:

• Time increments from 5 minutes to 4 hours, or a custom value, set under the booking page's Scheduling policy or per service.
• Documented buffers. Microsoft says buffer time counts toward availability. A 60-minute service with a 15-minute buffer needs a free 75-minute block and fills 75 minutes of your calendar.
• Different start placement. Shared pages walk each free block and keep starts at least one increment apart. A 45-minute increment on a 10:00–12:15 block gives 10:00, 10:45, 11:30. A custom 40-minute increment for 30-minute meetings gives 10:00, 10:40, 11:20.

Buffer time without longer meetings explains the increment trick, and odd start times on shared pages explains why shared-page starts aren't tied to the clock. Shared booking pages vs Bookings with me covers what else changes, and availability that doesn't match your work hours covers the other inputs.

BookingsXP is independent and not affiliated with or endorsed by Microsoft.