Type Heure HTML revient à 24 heures pour le changement à 12 heures

 If your computer's system prefs are set to use a 24-hour clock, the browser will render the <input type="time"> element as --:-- (time range: 00:00–23:59). If you change your computer's syst prefs to use 12-hour, the output won't change until you quit and relaunch the browser.
Blushing Baboon