What does 'hrs' stand for in military time notation?

In military time notation, 'hrs' stands for "Hours." This terminology is used to express time in a 24-hour format, which is standard in military and professional contexts to eliminate confusion between AM and PM. For example, 1300 hrs indicates 1:00 PM. Using 'hrs' helps streamline communication and ensures clarity in operations, especially when precise timing is crucial for missions or schedules.

The other options do not relate to the standard time notation used in military contexts. For instance, "History" and "High Risk" are terms used in entirely different contexts and have no affiliation with time notation. "Hourly Regimen" implies a scheduled plan that might involve hours but does not specifically define the way time is represented in the military format.