How to Trigger Zaps at Any Time Using Slack Reminders

A practical field guide from Automation Ace.

How to Trigger Zaps at Any Time Using Slack Reminders

Zapier's built-in Schedule trigger fires at fixed intervals — every hour, every day, every week. That works well for recurring automations, but there are many situations where you need to fire a Zap at a specific future time that you decide on the fly: follow up on a proposal in three days, process a batch of records at the end of the week, or send a report at 9 AM on a particular date. Slack's /remind command offers a simple solution: set a Slack reminder for yourself or a channel, and build a Zap that triggers when that reminder fires. The result is a flexible, human-controlled trigger that any team member can set from within Slack.

How Slack Reminders Work as a Zap Trigger

Slack's /remind command creates a reminder that Slackbot delivers to a user or channel at a specified time. The Zapier Slack integration includes a New Reminder trigger (or you can use the reminder delivery as the trigger event depending on your Zapier Slack app version). When a reminder fires and the message matches a pattern your Zap is watching for, the Zap executes.

The key insight is that the reminder message text can carry instructions or data. By including a keyword or structured text in the reminder, you can build a Zap that only fires on reminders containing that keyword — preventing every Slack reminder from triggering the automation.

Two Approaches: Reminder Created vs. Reminder Delivered

There are two points at which Zapier can respond to a Slack reminder:

• When a reminder is created: The Zapier Slack trigger "New Reminder" fires when /remind is used. This triggers immediately when the command is entered, not at the delivery time. Useful if the creation of the reminder (not the delivery) is the signal you need.
• When Slackbot delivers the reminder: Slackbot posts the reminder message to the user's DMs or to the channel. This can be caught by a Zap using the "New Message Posted to Channel" or "New Direct Message" trigger, filtered by the sender being Slackbot and the message containing a specific keyword. This approach fires at the time you specified in the /remind command — which is typically what you want for time-delayed triggers.

The delivery-based approach is the more flexible pattern for time-based triggering, because the Zap fires at the scheduled delivery time rather than immediately when the command is run.

Step-by-Step: Setting Up a Slack Reminder Zap Trigger

Step 1: Choose a dedicated channel or use DMs

Create a dedicated private Slack channel (e.g., #zap-triggers) where reminders that should trigger Zaps will be sent. This keeps Zap-triggering reminders separate from regular notifications and makes the filter logic cleaner. Alternatively, use your own Slackbot DMs if only you will be setting reminders.

Step 2: Define a trigger keyword

Choose a keyword or prefix that will appear in reminder messages that should trigger the Zap — for example [ZAP], TRIGGER:, or a specific phrase unique to this workflow. Every reminder intended to fire the Zap must include this keyword. Example reminder command:

/remind #zap-triggers "[ZAP] send-weekly-report" at 9am Friday

Step 3: Build the Zapier Zap

1. In Zapier, create a new Zap and choose Slack as the trigger app.
2. Select New Message Posted to Channel as the trigger event (for a channel-based approach).
3. Connect your Slack account and select the #zap-triggers channel (or the DM channel with Slackbot).
4. Add a Filter by Zapier step immediately after the trigger. Configure the filter to only continue if:
   • The message sender username contains "slackbot" (so regular user messages don't trigger the Zap)
   • The message text contains your trigger keyword (e.g., "[ZAP]")
5. Build the remaining Zap actions — these run only when a Slackbot reminder containing your keyword is delivered to the channel.

Step 4: Embed data in the reminder message

The reminder message text is available as a Zap field, so you can embed dynamic data in the reminder for the Zap to parse. For example:

/remind #zap-triggers "[ZAP] process-order order_id:4521 client:acme" tomorrow at 10am

In the Zap, use a Formatter by Zapier text step or a Code step to extract the values from the message text. This lets team members pass simple parameters to the Zap through the reminder without needing any form or interface.

Practical Use Cases

• Delayed follow-up: A sales rep closes a call and sets a Slack reminder to trigger a follow-up email Zap in two days: /remind me "[ZAP] follow-up email:prospect@example.com" in 2 days
• Time-boxed batch processing: An ops team member sets a reminder to fire at month-end to trigger a report generation Zap
• Ad hoc notifications: Set a reminder for a specific time to trigger a Zap that posts a summary to another channel
• Soft deadlines: A project manager sets reminders tied to project milestones that trigger status-update Zaps when each milestone date arrives

Limitations and Considerations

• Zapier Slack trigger is polling-based: The Slack "New Message Posted to Channel" trigger polls on Zapier's standard interval for your plan (1–15 minutes). There is a delay between when Slackbot delivers the reminder and when Zapier detects it. For time-critical workflows, this approach is not precise to the minute.
• Filter is essential: Without a filter on sender and keyword, every Slackbot message in the channel would trigger the Zap. Always add the Filter step.
• Slack reminder limits: Slack does not limit the number of reminders, but this pattern works best for infrequent, intentional triggers — not as a substitute for Zapier's Schedule trigger in high-volume recurring scenarios.
• Team awareness: Anyone with access to the trigger channel can fire the Zap. Document the keyword and expected format so the trigger is used correctly.

Slack reminders turn every team member into an on-demand Zap trigger, without giving them access to Zapier. It is a lightweight pattern that works especially well for teams that live in Slack and want to kick off workflows at ad hoc times without building a form, an interface, or a separate scheduling system.

For recurring scheduled Zap triggers, see Zapier's built-in Schedule by Zapier tool covered in the Zapier built-in tools guide. For Slack automation patterns more broadly, see the Slack automation for operations teams guide. For help building a Slack-triggered workflow, talk to Automation Ace.