That would be between solar cycles and lunar cycles: seems enticing. That would make Methuselah 80yo when he reportedly died; but there are problems still as Seth (for example) became a father at 105, which if it were months would be 8¾ years.
Another possibility is that when it says Methuselah it just means "Methuselah's blood line" or "Methuselah the tribe"; it's a Hebraic thing (elsewhere in the OT) to refer to a tribe as if referring to the founding person.
Or, the person writing down the numbers used a different system, through error or otherwise.
I don't remember anyone mentioned living for _thousands_ of years. There are plenty of characters that live for hundreds, though. It is believed that Abraham lived to the age of 175, while I believe there was one character that lived into the 300's, but I do not recall their name. It has been a while since I delved into the old testament.
> Said to have died at the age of 969, he lived the longest of all figures mentioned in the Bible.
The other story mentioned in the Quran is about a group of people and their dog who slept in a cave for 309 years and woke up afterwards. I believe they died shortly after. There is an actual chapter in the quran about this called the cave[1].
edit: Found it on the wikipedia page you linked. I was thinking about Enoch, Methuselah's father, who lived to be 365 years old according to the bible.