Triptolemus' Almanac is an almanac created by the minor god Triptolemus.
The almanac is a leather-bound book with a title in gold-lead and in a language that Leo Valdez couldn't understand. Along with the writing, it has a lot of different illustrations including scythes, different plants, a picture of the sun and a team of oxen pulling a cart.
After the Kerkopes are defeated, Leo Valdez goes through their treasure, attempting to find what Hecate was talking about. After claiming Odysseus' Astrolabe for himself, Leo locates the almanac. Although none of the text makes any sense to him nor does he see how the illustrations can help, the dwarfs explain that they stole it from a minor god in Venice, the next location that Hecate said that they needed to visit. Leo and Jason Grace force the Kerkopes to tell them where they can find the god, but the two are unable to pronounce his name. Leo decides to make a deal where the demigods recover their own stolen goods, claim the astrolabe and the book and allow the dwarfs to keep the rest of the treasure and their lives in exchange for the dwarfs helping to slow down the Roman army on its way to Camp Half-Blood. Leo also promises not to tell the god where they got the book from.
After finding Triptolemus, Frank Zhang returns the almanac to the delighted god, although he lies that they found it in the possession of terrible monsters. Frank asks Triptolemus to turn Nico back to normal and to heal Hazel from her poisoning since they brought the book back to him, but although the god is grateful and willing to let Frank go, he refuses to help Nico and Hazel due to his long-standing problem with Hades. Eventually, Frank makes a deal with Triptolemus for his friends and the god's help with the House of Hades after explaining that Hecate had led them to the book and that Hazel is one of the Titaness' favorites.