Just reaching out to the community again. Is there a way to customise the task list in calendar view to add additional standard fields and custom fields? And can I add fields from the Project the task is associated with, such as the Project ID?
Customize task doctype, adding a new field (Custom subject). You can even hide it. Use a client script to fill the custom subject field with your project data … Then, create a calendar view (search on awesome bar). Use your custom subject field.
Override task_calendar.js and get_events on backend method . Best way is creating a custom app instead modifying base code directly.