Beings suffer in woeful states and enjoy pleasant worlds in accordance with their karma. Their age-limit differs according to the gravity of the unskillful/skillful deed. Some are short-lived, and some are long-lived.
Queen Mallika, wife of King Pasenadi of Kosala, for instance, suffered in a woeful state for only seven days. On the other hand, Devadatta -- who attempted to kill the Buddha, cause a schism in the Sangha, and encouraged Prince Ajatasattu to kill his father (the stream-enterer King Bimbisara) among other things -- is destined to suffer for an aeon.
At times, earthbound deities live for only seven days."
Reference: A Manual of Abhidhamma (a translation by Ven. Narada of the Abhidhammattha Saṅgaha of Bhadanta Anuruddhācariya (ed. of the original Pāli text) with English transl. and explanatory notes by Nārada Mahā Thera. 5th rev. ed., Kuala Lumpur: Buddhist Missionary Society, 1987.
Lifespan or life term (Pali, kappa) refers to the practical maximum length of life in various worlds under normal circumstances. Whereas it is said that Gautama Buddha could have lived an "aeon" (kappa) if he wished, it makes more sense to understand the term as "normal lifespan" in that instance. He passed away at 85 when, if Ananda had requested him, he could have lived to 120, which was the normal maximum life term at that time. It seems that 120 is still the lifespan in the human world, perhaps having already dropped to 100.
Clearly, this is neither an average nor an absolute ceiling. This being the case, when cosmological detail like lifespans of demigods, high divinities, or denizens of the unfortunate destinations are given, they should be understood as gross generalizations. Individual circumstances vary as discussed above.
Furthermore, the measurement is difficult since lifespans on earth used to be much longer. In Buddhist Birth-Stories: Jataka Tales translated by C.A.F. Rhys Davids (translated from Prof. V. Fausboll's edition of the Pali text by Mrs. Rhys Davids, p. 81 ff.) is "the story of the lineage." It details the lives of previous buddhas, their chief disciples, lifespans, heights, and so on. Surprisingly, since these buddhas appeared aeons (inconceivably long periods) ago in the human world, they were much taller and lived much longer, even 80,000 years.
Therefore, our assumptions about human life are not accurate, and cannot be generally stated, how much less the details of other worlds? Any time spent in a hell of torment (rather than simply the miserable hells) would seem an eternities. The elapsing of an age, epoch, or world-cycle is inconceivable even under normal circumstances, all the more under duress.
