This month GW began to make various notations—words, names, abbreviations, letters, numerals, symbols, and other marks—in the margins of the monthly astronomical calendars printed in his almanacs. There are few substantial clues to the meaning of these casual jottings. Varying greatly in form and seldom having any apparent relation to corresponding diary or almanac entries, they appear at random over two widely separated periods: June 1764–Nov. 1775 and Feb. 1795–Dec. 1798. In most cases the editors can make no sense of them, but some can be understood. During the summer of 1770 GW used the calendar pages for a health record, counting his stepdaughter Martha Parke Custis’s recurring epileptic attacks for a period of about three months (see main entry for 31 July 1770). During 1772 and 1774 the calendar notations served on several occasions to remind him of future obligations. The abbreviation “Fred” next to 15 Sept. and 23 Nov. 1772 meant that he had business in Fredericksburg on those days, and another notation next to 18 Sept. 1772 apparently told him that he must return to Mount Vernon by that date for a court-ordered survey and division of land that involved him. Several days in Nov. 1774 were similarly designated for the sale of a friend’s lands (see main entries for 20–27 Nov. 1774). As aids to memory and measurement, GW’s notations in each of these cases served the same general purposes that the other parts of his diaries did, but without duplicating the exact functions of those other parts (see illus., p. 328).