Book of Enoch (1 Enoch) 74:17
And the year is accurately completed in conformity with their world-stations and the stations of the sun, which rise from the portals through which it (the sun) rises and sets 30 days.
Background and history of Book of Enoch (1 Enoch), and issues with this book.
R. H. Charles, The Book of Enoch (London: SPCK, 1917), public domain. The verse text is the English Wikisource transcription of that translation. Charles’s editorial signs are kept. He rearranges some verses in chapters 5, 39, 90, 91, and 106, so those chapters are not a straight 1, 2, 3 sequence.