Perpetual calendar
| Type: | Perpetual calendar |
| Geometry: | Circular, concentric |
| Unit of measurement: | Days of year |
| (Numbering) starts at: | 1 |
| (Numbering) ends at: | 28 |
| Numbered: | Every 1 |
| Repeats: | 1 times |
| Divided every: | 1 (Days of year) |
Scale located on: Tympan, Womb or Back .