What bugle call is played to wake up most soldiers worldwide?

Reveille: 7 A.M.‐ The morning bugle call, known as Reveille, was originally conducted as "Troop" in 1812 and was designed to muster the unit or for roll call, but as time passed it came to mark when the flag was raised in the morning and honors paid to it.

"Reveille" is a bugle call, trumpet call, drum, fife-and-drum, or pipes call most often associated with the military; it is chiefly used to wake military personnel at sunrise. The name comes from reveille, the French word for "wake up". (And in case you haven’t heard it spoken, the American pronunciation rhymes with “Beverly.”)

The counterpart of Reveille is Retreat, typically played at the end of the active-duty day. (This is often, but not always, at 5 pm.) Retreat, in turn, is followed in the daily routine by Taps, which signals the start of quiet hours (often 9 pm).