Google’s main aim is to gather all sort of information out of people all around the world in their servers. Main obstacle doing that is the language barrier. If someone can provide facility to support your mother language it can get close to your heart.
Google introduce 38 languages with Google calendar. The new languages are Latvian, Romanian, Filipino/Tagalog, Serbian, Ukrainian, Bulgarian, Hindi and Indonesian. Hope to see Sinhala in near feature.
Official Gmail Blog: Get your Google Calendar in 38 languages