Duration/Durable Etymology

Research into time management and creative production has led me to this:

Duration (n): late 14c., from Old French duration, from Medieval Latin durationem (nominative duratio), noun of action from past participle stem of Latin durare “harden”.

Durable (adj): late 14c., from Old French durable (11c.), from Latin durabilis “lasting, permanent,” from durare “to last, harden”.