calendar.google.com - Best Free Online Calendar SoftwareGoogle Calendar is a free online calendar service. It lets you schedulde events, and share your schedule with friends and family. You can choose to be reminded of upcoming events by email or pop-ups.
There are also a number of public calendars you can add to your private schedule, such as phases of the moon, holidays (including US holidays, UK holidays, Swedish holidays, Indian holidays, Christian holidays etc etc), and many more.
Events can be viewed by day, week, month, 4 days or in an agenda view.
Googel Calendar is easy to use, and the ability to easily add any friends's calendar and see it side-by-side with your own is a huge advantage.