What term is shouted to actors backstage by stage management when the show will begin in thirty minutes?

The term that stage management shouts to actors backstage when a performance is set to begin in thirty minutes is "Half." This call serves as a reminder for the cast to wrap up their preparations and get into their costumes or make any final adjustments as they prepare to go on stage. It is part of a series of calls that occur as the showtime approaches, with subsequent calls indicating shorter intervals until the show begins, such as fifteen minutes, ten minutes, and so forth.

The use of "Half" is a standard practice in theatre production to keep everyone informed about the timing and ensure that the performance starts on schedule. It sets the stage for a smooth transition into the next phase of the production process.