Seven-segment layout: a across the top, b top-right, c bottom-right, d across the bottom, e bottom-left, f top-left, g across the middle. Common anode ties all anodes to VCC and lights a segment by driving its pin LOW; common cathode ties all cathodes to ground and lights a segment by driving it HIGH. We design for common cathode (logic 1 = ON) — for common anode, invert your outputs. A dash is segment g alone, with every other segment off.

Input-to-position mapping: 000 → month tens, 001 → month ones, 010 → dash, 011 → day tens, 100 → day ones, 101 → dash, 110 → year tens, 111 → year ones. X is the most significant bit and Z the least.