Jalali GCal has a major update, version 3.0.
- It's updated to recent changes by Google on the Calendars's HTML code;
- now uses jQuery for some operations, which makes it somehow faster now and later updates will be easier as well;
OTOH I found this handy Firefox/Greasemonkey extension named Greasefire, which lists all available user-scripts (from userscripts.org) for current site in just one click, and you can install them rightaway!
The exciting news is that Jalali GCal has the 6th place in the list of scripts for Google Calendar in Greasefire (actually userscripts.org)!