27 + 3 = 30

27 + 3 = 30 We can now further divide the wheel of time: there are 27 fixed stars (nakshatras) along with three attributes that divide the time in smaller portions. So this 27 + 3 = 30 is interpreted as 30 degrees or days of one part of the wheel (circle) or month. All of this is only half of a day. The night is yet unaccounted for. Therefore, we multiply these 30 degrees by 2. This gives us our reference of 60 seconds in a minute. Thus the 360º x 30º = 10,800. Zero {0} is considered ‘Purna’ or complete. So we take out the last zeros and are left with 108. The idea of our total universe is represented by this number of 108. Offering 108, devotees believe that they are showing ultimate or complete respect to the Supreme. Cited from Website Hindu Astronomy