Unfortunately there is no “Hindu Community” Google calender. There are few Hindu calender but none of them are acceptable by all Hindu community. Hindu community is wide and diversified.
Hindu speak several languages, divided into several Indian states and various locations of the world; Hindu has several various festivals. To cover all of these Hindu evens and festivals are huge task and need community efforts. One person or small group of people can’t do this job entirely. So we all Hindu need to community effort to create comprehensive Hindu Community calender.
Calender is available at this link https://www.google.com/calendar/ical/itapplication.net_oci5lqpqs9eu9et2s5qb2ensco%40group.calendar.google.com/public/basic.ics