Seshat is frequently described as one who records history through the use of numbers, measurements, arithmetic, counting, and noting dates and time periods.
This is especially connected to keeping track of a pharaoh's successes, triumphs, years of rein, and jubilees, including the Sed Festival which was a 30-year jubilee. She was, in later eras, also tasked with recording the pharaoh's military campaigns. Pharaohs thought it was fortunate if she recorded their deeds and all of them, in death, wanted her to inscribe them on the Tree of Life.
In The Gods of The Egyptians, E. A. Wallis Budge describes different images of Seshat in which she is taking historical notes in the form of numbers. "Elsewhere, we see her without her panther-skin garment, holding a writing reed in the right hand, and the cartouche symbolic of her name in her left," he writes. "In this form, she suggests the idea of being a kind of recording angel, not so much, the deeds committed by man, but of their names, of which she, presumably, took note, so that her associate Thoth might declare them before Osiris."
In a title that accompanies the image, he says she is called, "great one, lady of letters, mistress of the House of books." But in another scene, "she holds a notched palm branch in her hand, and she appears to be counting the notches." The lower end of the branch rests on the back of a frog, seated upon the emblem of the ankh and another part of the image shows the symbol for the double Sed festival, which indicates she counting up and recording history related to the pharoah.
"Seshat appears in the character of the chronographer and the chronologist; the use of the notched palm branch is a symbol of the counting of years," Budge writes. This is a custom that probably goes back to pre-dynastic times.
Budge describes another image in which a column of hieroglyphics spells out "life," and "power," and "30 your festival." There is a seated figure with an Ankh in each hand. Seshat is writing "life," and "millions of years." There is a passage in which she declares to a king that she has inscribed him on her register. She notes half a period of life which shall be "hundreds of thousands of 30-year periods," and that she has ordained that his years shall be upon the Earth and that he shall live forever.