Could some on recommend a great but simple calendar?

Functionality which i require is like in this website - .

enter image description here

As you can tell, if in date is really a publish or event then your date has grey background and when you hover onto it you can observe the publish or event.

I'll attempt to modify it to show my coustom posts from wordpress, because I didn't find what other wordpress wordpress plugin.

My suggestion is one thing like jQuery UI Datepicker:

It has good features, along with a good documentation, and isn't very difficult to change.

You may also chose different styles, and personalize it for your needs.

I believe fullcalendar may fits your need. it's jQuery based calender, you can include occasions, have full charge of all occasions, a lot of api can also be well crafted, but it doesn't possess the feature you published here, that is things i want too. knowing such like, do tell me please.