Catch Double-Bookings Before They Become Problems
Double-bookings create stress and unprofessionalism. Notis watches for calendar conflicts and sends a Slack alert the moment two meetings overlap, so you can reschedule immediately.
Trigger
Webhook received
Notis starts this workflow when an external tool or custom backend sends an HTTP request.
Action
Create a reminder
Creates a slack reminder with specified text and time; time accepts unix timestamps, seconds from now, or natural language (e.g., 'in 15 minutes', 'every thursday at 2pm').
Why this helps
ADHD-related time blindness and rapid scheduling can lead to accidentally booking two meetings at the same time. This creates panic, burns trust with teams, and forces embarrassing last-minute cancellations.
- Catch conflicts in seconds, not minutes before a meeting
- Maintain professionalism by rarely cancelling at the last minute
- Reduce the panic and stress of discovering a double-booking
- Preserve relationships by staying reliable
Setup
Build it in a few focused steps.
- 1Connect Google Calendar and Slack to Notis.
- 2In the Automations tab, create a new automation called 'Double-Booking Alert'.
- 3Set the prompt: 'Monitor my calendar continuously. If any two events overlap or conflict in time, send me an immediate Slack alert with both event titles and times so I can reschedule one.'
- 4Set the trigger to 'Webhook' and allow Notis to monitor your calendar.
- 5Choose a Slack channel for urgent alerts (your personal DM recommended).
- 6Test by intentionally creating an overlapping meeting and verifying the alert arrives instantly.
Questions about this workflow
Will the alert trigger for back-to-back meetings with no buffer?
Tell Notis: 'Only alert me if meetings overlap by more than 5 minutes' to ignore tight-but-viable schedules.
What if I have a lunch block and accidentally book over it?
Yes, you'll get an alert. This reminds you to respect your own boundaries.
Can I set a time buffer?
Tell Notis: 'Alert me if meetings are within 15 minutes of each other' to add travel or transition time.
When this happens · Trigger
Do this · Action
Supported Triggers and Actions
Notis builds workflows that link Google Calendar to Slack. A trigger fires from one place; an action lands in another.
Google Calendar triggers
Slack actions
Attendee Response Changed
Polling trigger that fires when any attendee's RSVP changes to accepted, declined, or tentative. Returns attendee info and current status.
Set snooze duration
Deprecated: turns on do not disturb mode for the current user, or changes its duration. use `set dnd duration` instead.
Event Canceled or Deleted
Triggers when a Google Calendar event is cancelled or deleted. Returns minimal data: event_id, summary (if available), and cancellation timestamp.
Add a custom emoji to a Slack team
Deprecated: adds a custom emoji to a slack workspace given a unique name and an image url. use `add emoji` instead.
Event Starting Soon
Triggers when a calendar event is within a configured number of minutes from starting. Returns event details, time remaining, attendees, and join links when available.
Add an emoji alias
Adds an alias for an existing custom emoji in a slack enterprise grid organization.
Calendar Event Changes
**SOON TO BE DEPRECATED** - Use Calendar Event Sync (polling trigger) instead. Real-time webhook trigger for calendar event changes. Returns event metadata only. For full event data, use Calendar Event Sync (polling trigger).
Add a remote file
Adds a reference to an external file (e.g., google drive, dropbox) to slack for discovery and sharing, requiring a unique `external id` and an `external url` accessible by slack.
Event Created
Polling trigger that fires when a new calendar event is created. Returns event ID, summary, start/end times, and organizer info.
Add a star to an item
Stars a channel, file, file comment, or a specific message in slack.
Calendar Event Sync
Polling trigger that returns full event data including details, attendees, and metadata. For real-time notifications with basic info, use Calendar Event Changes (webhook).
Add call participants
Registers new participants added to a slack call.
Event Updated
Triggers when an existing Google Calendar event is modified. Returns the event ID, change type, and the specific fields that changed with their previous and new values.
Add emoji
Adds a custom emoji to a slack workspace given a unique name and an image url; subject to workspace emoji limits.
Add reaction to message
Adds a specified emoji reaction to an existing message in a slack channel, identified by its timestamp; does not remove or retrieve reactions.
Connect any two apps with Notis in the middle.
Not just Google Calendar and Slack. Any combination from 985+ integrations.
When this happens · Trigger
Do this · Action
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