Add a calculation in google calendar (gadget or extension)

I want a small automatically calculation in google calendar. Suppose I have several calendars: for each project one. It contains tasks and events. A task can be recognised by using X as first letter in the title of the event. I need somewhere to put 2 parameters: 1. the acceptable workload per day 2. the acceptable workload per week What i want is: a) near the daydate in the google calendar 1. total hour calculation of all tasks (X) of active calendars 2. total hour calculation of all events (X) of active calendars 3. Total of 1 & 2 = daily workload (if it is lower than the accpetable workload per day then it is green / if not it is red) b) near the week (or on the first day of my week) 1. The total hours of planned tasks 2. The total hours of planned events 3. Total of 1 & 2 = weekly workload (if it is lower than the acceptable workload per week, then it is green / if not it is red. See example in attachement