Online Calendar

The thing topmost on my agenda right now is to find a non-tech kind of online calendar maker, that will obviously make sure that I do not end up missing my appointments, meetings, and of course, personal occasions. So far, I had a free SharePoint from CloudAppsPortal that is doing its job as a calendar software but now I think I should try out something else that is quicker and easier while on the go. I open to paid software but it should run smoothly without hassles on multiple gadgets as well as on the PC. Does anyone have any experience with multiple online calendars and can tell me the best one to go for? Suggestions and ideas would be most welcome.