Use Book Time Off in Slack

Approve leave from a DM in one click, book time off without leaving Slack, post a daily who’s-off summary into a channel, type /whosoff anywhere, and let everyone’s Slack status show “On leave” automatically.

Updated June 2026

Quick answer

An admin goes to Settings › Connected apps, finds the Slack card and clicks Connect Slack workspace (a one-time approval in Slack). Then pick a Daily digest channel and tick Post the daily digest automatically. Each person can also click Connect your Slack so their status shows “On leave” while they’re off.
Find it under Settings › Connected apps › Slack

If your team lives in Slack, leave can live there too. One workspace connection covers everyone: holiday requests arrive as a DM with Approve and Decline buttons, anyone can book time off from a form inside Slack, a who’s-off summary posts each morning into a channel you choose, and approved leave sets a “On leave” Slack status automatically. Nothing replaces the app or the email approvals; Slack is simply another place the same requests show up.

What you get

Connect the workspace (admin, once)
Go to Settings, then Connected apps, and find the Slack card. Click Connect Slack workspace. Slack asks you to approve access once; some workspaces route this through a Slack admin first. After that, the whole team gets request DMs, the daily digest and /whosoff with no per-person setup.
Pick the digest channel
Back on the Slack card, choose a Daily digest channel from the dropdown and tick Post the daily digest automatically. Click Send test digest now and check the channel. The send time, bank-holiday and birthday options are shared with the Teams digest, under Notifications.
Connect your own Slack (each person, optional)
On the same card, click Connect your Slack (it is also in the You menu as Connect Slack). This is what lets Book Time Off set your own status to “On leave” automatically while you’re off. DMs, the digest and /whosoff work without it.
Try it
Type /whosoff in any channel, open the Book Time Off app in Slack’s sidebar to see the Home tab, and book a test request to watch the approver’s DM arrive with its Approve and Decline buttons.
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People are matched by email

Slack DMs and statuses find each person by email, so someone’s Slack account must use the same email address as their Book Time Off login. If a DM doesn’t arrive, that mismatch is the first thing to check.

Private by design

Book Time Off only sends messages and sets leave statuses; it never reads your conversations. Personal request DMs stay between you, the bot and your approver. The only thing that posts to a channel is the who’s-off summary, in the one channel an admin picks.

Frequently asked

Do approvers have to use Slack?

No. The one-click email approvals and the app’s Inbox carry on exactly as before. Slack is an extra place the same request appears, not a replacement, so a manager who lives in email and a manager who lives in Slack can both approve in one click.

Can I see the full calendar in Slack?

Slack can’t show a real calendar grid, so the Home tab, the digest and /whosoff give you summaries: your balance, upcoming leave and who’s off in the next seven days. For the full picture, open the app, or subscribe a calendar to the iCal feed.

Why didn’t the requester get a Slack DM after I approved from the email?

Decisions made inside the app send the requester a Slack DM. Decisions made from the email’s Approve or Decline buttons currently confirm by email only; the booking, calendar and status sync all update either way.

Does the digest post when nobody is off?

No. Days with nothing to report post nothing, and by default it stays quiet on bank holidays too, so the channel never fills with empty updates.

What does my status actually show?

While you’re on approved leave your Slack status shows “On leave” with the date you’re back, and it clears automatically when you return. You need to have clicked Connect your Slack once for this to work.

Can I sign in with Slack?

Yes. Once your company’s workspace is connected and your Slack email matches your Book Time Off email, the sign-in screen offers Sign in with Slack alongside email and Microsoft.

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