In His discourse of 29 September 1960 (Chapter 31 of Sathya Sai Speaks volume 1), Swami said,
"I will be in this mortal human form for 59 years more and I shall certainly achieve the purpose of this avatar; do not doubt it. I will take My own time to carry out My Plan so far as you are concerned. I cannot hurry because you are hurrying.
I may sometimes wait until I can achieve ten things at one stroke; just as an engine is not used to haul one coach, but awaits until sufficient haulage in proportion to its capacity is ready. But My Word will never fail; it must happen as I will."
That would mean that Swami would give up His body at the age of 93 or 94, since He was born on 23 November 1926. But He gave up His physical form on 24 April 2011 (Easter Day) at 7:40AM, at the age of 84. What is the explanation for this seeming discrepency?
The explanation is that Swami was talking in lunar years, not calendar years. Swami has done this before ---see the story below the horizontal line at the end of this webpage.
There are 12 lunar months in a lunar year. Several people have given calculations showing that Swami was 94, 95, or 96 lunar years old when He left His body. Each of the calculations gives a different estimate of the number of days in a lunar month, and that is why there is a difference. We wait for a Hindu scholar/astrologer to tell us the exact age, based not on average lunar months but on the actual number of lunar months that passed from His birth to His leaving the body. Then we will know exactly how old Swami was.
But the major point is that Swami appeared to be talking in terms of lunar years and not calendar years, and that is why everyone has been confused.
Here is one quick calculation. Swami lived 30,833 days. Lunar months average 27.21 days (a number found on the internet, but it may not be correct), and there are 12 lunar months in a lunar year. Thus, Swami lived about 1133 lunar months, or 94.4 lunar years.
This incident, which took place in 1986, gives a precedent for Swami usng lunar years.
Ghandikota Aryama's grandfather was the late B. Sri Ghandikota Subrahmanya Sastry, a famous Sanskrit pandit and devotee of Swami, to whom the Sai Gayatri was revealed. When the grandfather gained merger with Swami in 1986, at the age of 93, Swami came to their flat in Prasanthi Nilayam and stated that the grandfather was a maharishi and had reached the age of 100 years (even though he was 93).
Later, Aryama asked his father, B. Sri Ghandikota Subba Rao, about the discrepancy. B. Sri Ghandikota Subba Rao said that Swami uses the traditional Indian Lunar years, based on lunar months not adjusted for the solar years, in determining a person's lifespan. 12 lunar months make 1 lunar year. 100 such lunar years equaled 93 years for Aryama's grandfather.