primary time

noun3

1. •
   The amount of time in which a pilot is actively controlling the aircraft, excluding time flown while instructing and evaluating.
2. •
   Time as directly experienced, as opposed to time as a measured amount, historical time, etc.

   • Observing mistakes in understanding of primary time leads to the conclusion that the deaf child has little sense of historical time or that the created concepts are inadequate. — 2004
3. •
   The point in time when something is initiated; the start time.

   • The expression "the time in which" a change occurs may refer to the primary time, i.e. the precise time during which the change occurs, or to a time which includes the primary time — 2021