Was Methuselah literally 969 years old when he died?
Genesis 5:27 (NASB)
Thus all the days of Methuselah were nine hundred sixty-nine years;
and he died. But were these years the same as the duration of today's
12-month duration calendar years? Did Methuselah literally live 969
365-day years?
God purposed for Adam ,a perfect human to live for ever, subject to him being obedient to God.(Genesis 2:15-17) However because of hid disobedience, Adam forfeited that opportunity for himself and his descendants,.Romans 5:12
Yes, Methuselah literally lived 969 years - of 12 months per year.
From the two verses below (Gen 7:11 and 8:3-4) we can establish that 150 days amounted to five months.
Genesis 7:11 (NASB)
11 In the six hundredth year of Noah’s life, in the second month,
on the seventeenth day of the month, on the same day all the fountains
of the great deep burst open, and the [a]floodgates of the sky were
opened.
Genesis 8:3-4 (NASB)
3 "And the water receded steadily from the earth, and at the end of
one hundred and fifty days the water decreased. 4 In the seventh
month, on the seventeenth day of the month, the ark rested upon the
mountains of Ararat."
From the verses below we read that the top of the mountains became visible on the first day of the tenth month, Noah waited for a further 40 days, then opened the window of the Ark. In verse 10 says, that Noah waited for seven days and yet a further seven days wait (verse 12) and sent out the dove and the dove did not return.
Genesis 8:5-6,10 New American Standard Bible (NASB)
5 "The water decreased steadily until the tenth month; in the tenth
month, on the first day of the month, the tops of the mountains became
visible. 6 Then it came about at the end of forty days, that Noah
opened the window of the ark which he had made." 10 "So he waited yet
another seven days; and again he sent out the dove from the ark."
Genesis 8:12-14 (NASB)
12 "Then he waited yet another seven days, and sent out the dove; but
she did not return to him again. 13 Now it came about in the six
hundred and first year, in the first month, on the first of the month,
the water was dried up from the earth. Then Noah removed the covering
of the ark, and looked, and behold, the surface of the ground was
dried up. 14 In the second month, on the twenty-seventh day of the
month, the earth was dry."
Conclusion:
From the two verses Genesis 7:11 and Genesis 8:3-4 we can establish that 150 days amounted to five month .The fact that Bible mentions the 10 month, and a subsequent period of 40 days and at least two-seven day periods for this year, indicate that the year was 12 months long.
A year of 12 months , 30 days each, falls short 5- 1/4 days of a solar year of 365 -1/4 day. The Bible to the best of my knowledge does not indicate ,if at the time of Methuselah , any adjustment was made when the seasons were falling behind. It is logical, however that from the observation of the vernal or autumnal equinox, to provided a guide that the seasons were falling behind and that adjustment of the calendar was required.