Inner ring (12 states): duodecimal digit
Outer ring (5 states): base-5 digit
This is a mixed-radix counter: 60 = 5 × 12.
For each step of the inner ring (0→↋), the outer ring stays. After inner wraps, the outer advances by 1.
Examples
0 → (0, 0) • 11 → (0, {{ digit12(11) }})
12 → (1, 0) • 47 → (3, {{ digit12(11) }})
59 → (4, {{ digit12(11) }})
Why 12×5?
12 has divisors 2,3,4,6 → clean fractions. 5 keeps the outer wheel compact.
Together they yield 60 states—the same structure behind minutes/seconds and degrees.