A “gurre-nâme,” used to determine the day of the week corresponding to the beginning of each Hijri month, appears in Ottoman literature in calendars, astronomical treatises, or independently as tables or circular forms. Our example of a circular gurre-nâme is found within an anonymous collection of gurre-nâmes. Comprising concentric inner and outer circles, this gurre-nâme has a movable inner circle. Due to this feature, it also represents an Ottoman volvelle. While the outer circle contains the names of the Hijri months, the inner circle displays the names of the weekdays and numbers from 1 to 8. Information on how to use the volvelle can be obtained from the explanations provided above and below the volvelle.