How can I configure n8n's Wait Node to pause 24 hours before an appointment?

Below is a checklist to ensure your Wait node pauses until 24 hours before the appointment time as expected:

1. Use the “At Specified Time” Option:
   To wait until a moment relative to an appointment, set the Wait node to “At Specified Time.” Then, use an expression to calculate the appointment time minus 24 hours.

2. Calculate the Correct Date and Time:
   For example, if your incoming data includes the appointment time in a field called appointmentTime, you can use an expression like this in the Date and Time picker:

   JSCopied
   new Date(new Date($json.appointmentTime).getTime() - 24 * 60 * 60 * 1000)

   This expression subtracts 24 hours (converted to milliseconds) from the provided appointment time.

3. Ensure the Result is in the Future:
   If the computed date and time is already in the past relative to the workflow’s execution time, the Wait node will resume immediately. Double-check that the calculated time (appointment time minus 24 hours) is indeed still upcoming when your workflow runs.

4. Time Zone Considerations:
   Remember that the Wait node uses the n8n server time for its calculations, regardless of your workflow’s timezone settings. If there’s a difference between your expected local time and the server time, adjust your calculation accordingly.

By confirming these points, you should be able to have the Wait node pause until 24 hours before an appointment as intended.