Seven Eternities
Seven Eternities is a phrase used in Stanza I.1 in The Secret Doctrine to refer to the duration of a Maha-Pralaya and a Maha-Manvantara (or Maha-Kalpa):
The Seven Eternities meant are the seven periods, or a period answering in its duration to the seven periods, of a Manvantara, and extending throughout a Maha-Kalpa or the “Great Age”—100 years of Brahmâ—making a total of 311,040,000,000,000 of years; each year of Brahmâ being composed of 360 “days,” and of the same number of “nights” of Brahmâ (reckoning by the Chandrayana or lunar year); and a “Day of Brahmâ” consisting of 4,320,000,000 of mortal years.[1]
However, the phrase "seven eternities" can also be applied to the duration of a smaller cycle:
The opening sentence of Stanza I., when mentioning “Seven Eternities,” is made to apply both to the Maha-Kalpa or “the (great) Age of Brahma,” as well as to the Solar pralaya and subsequent resurrection of our Planetary System on a higher plane. There are many kinds of pralaya (dissolution of a thing visible), as will be shown elsewhere.[2]