This is a WooCommerce Booked Appointment based plugin. The project was about a Room Booking System. They had some rooms that can be booked or rented for some timeslots. The calendar was shown with the Booked Appointment plugin. I worked on a plugin that links the calendar with the appropriate products based on the timeslots.
There was another issue in the plugin that it used to let book the dates/timeslots that were already booked by someone else. It turns out that it was related a time issue at the midnight. I prepared a fix plugin separately so that the problem is fixed.
I have contributed around 80% to the project.