First off, if you use a calendar to remember to do tasks, it is most likely for events like appointments, meetings, birthdays, etc. Events, however, which you might want to consider adding are things which you probably don’t remember to do very often.

For example:

• Change the smoke detector batteries (twice a year)
• Change the air filter (every two months for me)
• Try to take over the world (get the reference?)

You get the idea. These are probably tasks which sometimes go forgotten until an ‘ah-ha’ moment where you do it. If you set these tasks as recurring events on your calendar, you won’t forget again.