When many clocks show 12 hours instead of one 24-hour ring, what older habit best explains the split?

Answer: Day and night counted separately

Workers preferred shorter dials — This sounds practical, but it reverses the story. The 12-hour pattern appears in ancient Egyptian timekeeping long before familiar mechanical clock dials became ordinary. The short dial is easier to read, yet that convenience is not the root cause of the split.

Day and night counted separately ✓ — This is the historical path. Egyptian timekeeping treated daylight and darkness as separate cycles, with 12 hours of day and 12 of night. The 24-hour idea grew from joining those two halves, so the 12-hour face preserves an older way of counting rather than a clean modern design.

Finger counting set the dial — Finger counting is a plausible reason the number 12 felt natural, because four fingers have twelve joints. But it does not by itself explain why a whole day became two 12-hour halves. The stronger trail is Egyptian daylight and night being counted separately.