Custom Recurrence is a Google Workspace Add-on for Google Calendar that lets you repeat calendar events according to your own repeating cycle. Say you follow a specific letter, number or color day pattern. Simply, upload your timezone, your cycle pattern, start and end dates, holidays and any additional dates to exclude via a Google Sheet Template. Weekends are automatically excluded. Then, by selecting an event on your calendar you will be prompted to select an end date for your recurrence. Then select one of three options for repeating your event according to your own pattern.