Jakub is on short vacation :)
Here is latest checked-in Calendar project. It takes 4 to >10 sec. to load Calendar with 70 events. Time depends on client PC (how fast it is) and network type (LAN, Internet).
If Calendar shows less events it is naturaly much faster, but 70 events is an avarange we expect. Our aim is to have <4 sec.to reload Calendar on avarange PC connected by Intenet.
For best results, use the Firefox browser..