Time Calendars are essential in a Jewish community. In the Middle Ages, Jews often included references to the calendar in manuscript compilations and prayer books. In the sixteenth century, so-called Evronot manuscripts developed in Ashkenaz. This coincided with the replacement of the Julian by the Gregorian calendar in 1582. Jews were similarly concerned with concepts of time and the heavenly spheres. Ashkenazic sages wrote explanations of the calendrical rules, often incorporating unique illustrations. 

An early example from the Braginsky Collection (no. 19) includes a figure on a ladder, carrying an hourglass, reaching for the secrets of the calendar. Another Braginsky Collection item (no. 20) contains similar illustrations. While both feature a ladder, the first contains a typical depiction of the moon with a human face. In an eighteenth-century manuscript from the NLI (no. 21), Issachar wears contemporary rabbinic garb as he receives an hourglass from a winged angel, emphasizing that knowledge of the calendar is a divine gift. 

Other discussions of time and heavenly bodies are more practical. For example, the blessing of the new moon depends on the calculation of the start of the new month. The image in NLI's small and attractive book of blessings (no. 22) is probably by a scribe named Israel, from Fürth, Germany.