OpenSlot · Guides

Outlook Scheduling Assistant vs. OpenSlot: which for what

These two tools read the same underlying data — Microsoft 365 free/busy — and solve different problems. Here's the honest split.

Use Scheduling Assistant when…

You are booking one internal meeting right now, all attendees are in your org, and you have the authority to just put it on calendars. It's built into the meeting form, shows the visual grid, and suggests times. For that job it's the right tool and OpenSlot adds nothing.

Use OpenSlot when…

The times need to leave Outlook as text. Offering slots to a client, a candidate, a vendor, or anyone who should choose rather than be booked; coordinating for someone else (the classic assistant workflow); or sending group availability into a Teams channel or external email thread. Scheduling Assistant has no "export what I'm seeing" button — OpenSlot's entire output is that button:

All times in US/Eastern
• Today 07/08
  03:30 PM - 04:00 PM
  05:00 PM - 05:30 PM
• Thursday 07/09
  09:30 AM - 10:30 AM
  12:00 PM - 01:00 PM
  02:30 PM - 03:00 PM

The practical differences

Output: a grid to read vs. a list to paste. Timezones: your own vs. any, stated on the first line. Range: built for the next few days vs. up to 60 days at once. Sharing: meeting invite only vs. copy, download, or insert into a compose window via the add-in. Most heavy schedulers end up using both — the Assistant to book, OpenSlot to communicate.