base 24 is a positional numeral system with twenty-four as its base. It uses 24 different digits for representing numbers. The digits for base 24 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, m, and n.

base 28 is a positional numeral system with twenty-eight as its base. It uses 28 different digits for representing numbers. The digits for base 28 could be 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, and r.