Hi everyone ! 
:oops:
Have a nice day !!! :cool
That calendar is nothing more than a formatted (using CSS) table. Those “Dates” that have an activity or URL associated with it just have a hyper link assigned to them. I presume that you could make use of a database to get the data for a particular date so that you know which date to put what hyper link to.
To generate the actual calendar, you may want to look closely at the following PHP functions:
mktime()
date()
time()
and it also could be helpful to look at
cal_days_in_month()
All can be found at http://www.php.net
All this being said, there are multiple questions regarding calendars on this forum as well as code snippits and examples. Did you make use of the “SEARCH” feature of the forum to find them? Many examples and I believe a couple of tutorials.
Problem is that there are more than one way to approach this.