Calendrical indication on clock and watch dials was one of three elements of dial content in the period 1550–1770, along with lunar and astronomical indications. The different cycles within the calendar year such as the period of the day and the seven days of the week were all significant. The way in which they were represented on dials changed and the number of calendrical units represented declined over time. It is only by comparing them with printed paper sources bearing similar information that it can be better understood. The calendar function was used for astrological purposes, but when astrology declined it continued to be important for religious and financial uses and became important during the reform of the calendar in the eighteenth century.