These days, keeping track of time—and of Jewish ritual moments—demands little of us: A swipe or a click and, presto, we know instantaneously when the sun is scheduled to rise and set and when Passover is destined to take place this year. If, like me, you’re given to planning ahead, you can even anticipate the dates of the High Holidays through 2050.Earlier generations of American Jews were not nearly as fortunate. Writing shortly before WWI about the perils and pitfalls of Americanization, one recently arrived Jewish immigrant named Marcus Ravage recalled in his memoir, An American in the Making, that in the New World, being aware of when Hanukkah—or, for that matter, any other yontef—took place was a losing proposition: “Did I know that last week was the Feast of the Maccabees? How could anyone know it in America?” To him, and countless others, nothing spoke more directly to their profound sense of dislocation than the disjuncture in temporal rhythms between the Old World and the New.At the time, American calendars, newly adorned with the latest technological innovation—brightly hued chromolithographs of sweet-faced children and alluring pastoral landscapes—were thick on the ground. For all their novelty, they contained no references to Hanukkah, Passover, or even Yom Kippur.To compound matters, a traditional luach, or Jewish calendar, which did refer to these and other Jewish moments, was not only difficult to obtain, but also increasingly difficult for American Jews to understand. A European import rather than a local product, it assumed a working knowledge of Hebrew and a certain degree of ritual proficiency, both of which increasing numbers of American Jews lacked.How, then, did they manage? Some American Jews relied on their local synagogue bulletin, or on pronouncements from the pulpit, or on word of mouth to keep abreast of impending holidays. By the 1910s, they could also avail themselves of a growing number of helpful guides produced by American Jewish publishers such as the Jewish Almanac Publishing Corporation, Bloch Publishing Company, and the Hebrew Publishing Company.Written in English, clearly laid out, and easy to use, the fancifully titled The Centurial (1918), for instance, ensured that American Jews could plot the next hundred years’ worth of Jewish ceremonial events, or, closer to hand, figure out when their son’s bar mitzvah would fall.Still other American Jews relied on their kosher butcher, the neighborhood grocer, and by the 1930s, the manufacturers of food products to keep them in the loop. Commercial interests, sensing an excellent opportunity to join community service and goodwill to profit, either commissioned a Jewish calendar or put their name to one already in production. What an artful way to flag time-sensitive products such as matzo for Passover, dairy products for Shavuot, flour for the weekly Sabbath.B. C. Friedman and Sons Matzoh Bakery of Philadelphia clearly thought so. Purveyors of matzo meal, matzo farfel, and a distinctive form of unleavened bread called protein matzo, a product “recommended by doctors for those suffering with diabetes,” the company furnished its loyal customers with a “calendar booklet for 5700” (1939-1940).In the years that followed, the B. Manischewitz Co.; Isidor Jacobson Wines and Liquors of Jackson Heights, New York (“your neighborhood store”); Drake’s Cakes (remember them?); Mueller’s Egg Noodles; the National Sugar Refining Company of New Jersey; and Samuel Sandler Kosher Sausage Manufacturing Company also made sure to keep their customers satisfied by offering their own, cost-free version, of the Jewish calendar, along with their best wishes for a “happy and prosperous New Year.”Once the Jewish calendar-cum-advertisement caught on, a wide array of institutions—banks, charities, funeral homes, Yiddish theater companies, and yeshivas galore—made use of one for their own ends: to promote a cause or an event, to draw in and reward customers. American Jewish calendars, varying in size and sponsorship, could now be found in abundance—and in any number of settings. Some were kept in a pocket or a purse, others in a drawer, and still others destined to be hung on a wall or the inside of a kitchen cabinet. Today, many of these items, avidly assembled and preserved by the collector Peter Schweitzer, are housed at the National Museum of American Jewish History.Although it nearly cornered the market, the commercialized Jewish calendar faced competition from another quarter: the National Federation of Temple Sisterhoods, the umbrella organization of Reform Jewish women, under whose aegis a decidedly more elevated approach to Jewish timekeeping—a “Jewish art calendar”—came into being. Intended to “Judaize the homes” of its members who had either grown rather lax in or increasingly indifferent to Jewish ceremonial life, it transformed the Jewish calendar from an exercise in consumerism into a vehicle of “religious consciousness,” heightening the appeal of Jewish rituals along the way.Much of that appeal was visual. Drawing on a battery of images that ran the gamut from a reproduction of Michelangelo’s Moses to Max Pollack’s drawing of a haluzah, a female Jewish pioneer, clad in a large-brimmed hat and skimpy shorts, the NFTS Jewish art calendar brought home “art’s ability to satisfy modern Jewish needs,” or so asserted Carrie Simon, the organization’s president, in 1917, shortly after the calendar’s debut. Years later, having expanded its portfolio to include photography, the Jewish art calendar offered its members “glimpses” of the modernist synagogues that now inhabited the suburban landscape from coast to coast. “A new synagogue architecture has appeared and is definitely on its way,” the text explained, eager to showcase its “beauty and distinctively contemporary character.”Like its commercial counterparts, the NFTS Jewish art calendar varied in size. At first, it was a fairly large and bulky composition made of cardboard; over the years, it slimmed down to 4 1/2 inches by 7 inches worth of paper; today, the NFTS is available online. In its earliest pre-digital iteration, the calendar’s loose pages were bound together by a silk cord or string; in later years, it came increasingly to resemble a spiral notebook or a community cookbook.Despite the calendar’s small proportions and short shelf life, its champions made much of it, likening the timekeeping device to “practically an essential item” without which the American Jewish household might falter. “Jewish holiday dates are all listed, so there is no last minute rush for Chanuko gifts, matzos, or Confirmation dresses,” explained “When Your Day Goes Topsy Turvey,” an article that appeared in the 1939 issue of the NFTS’ newsletter, Topics and Trends, touting the calendar’s virtues. A source of stability, the latter was also said to endow the woman of the house with authority, empowering her to join her newfound expertise on the rhythms and rituals of Jewish life to that of household management.Once you add up the number of American Jewish calendars of the 20th century and take stock of the expectations they generated—of a good meal, prosperity, knowledge, faithfulness—they come in their own as consequential, rather than disposable, artifacts of the modern Jewish experience. Aligning the personal with the collective, the Jewish calendar, it turns out, does more than keep time. It keeps modern Jewish life in circulation.***Like this article? Sign up for our Daily Digest to get Tablet magazine’s new content in your inbox each morning.