Go to Settings > Automations > New Automation.

Name your automation. Set the action to "Send Email" and select which email template you want to use. If you don't have an email template that you've created, click "Add new template".

Set the trigger to "Project date". Click on "Immediately", then select "Before" from the dropdown.

Choose how many days before the project date you wish to send this email. You can switch to minutes, hours, days, or months.

Enter the number of days or hours in the trigger section as well.

Use the rules section to specify who will receive this email. Leaving the rule section empty means there will be an email sent to every client with an upcoming project date.

You can use the rules section if you do not wish for everyone to receive this email. Set a "Specialty" rule, and only projects labeled with that specialty will receive this email.

Use the "Invoice status" rule if you only want to send this email to those who have paid.

Select "All rules must be met".

Scroll to the top of the page and switch the automation from "Draft" to "Active".

Click save at the bottom of the page.

Make sure your projects have project dates. This automation will not work otherwise.

After you save, the automation is active and will send a reminder email for upcoming projects.