When does the shot clock start, stop and reset?

Section 24 of the Official Rules and Case Book sets the shot clock at 30 seconds.

• Set to 30 at the start of each period and after a goal.
• Runs with the game clock. It starts when play starts and stops when play stops.
• Reset to 30 when the team in possession takes a shot on goal, control of the ring changes teams, or a delayed penalty is signalled (further delayed penalties before the stoppage do not reset it again).
• Also reset when a penalty makes the non-penalized team commit a violation and play stops, when a player on the team not in control commits a violation and play stops, when a player on the team not last in control is injured and play stops, or when the two shot clocks show different times during a stoppage.
• A shot on goal is a legal shot by the team in possession that enters the net, hits a post or the crossbar, hits the goaltender or acting goaltender in the crease, or hits the goaltender outside the crease and stops it entering the net.
• At zero an audible signal sounds, play is stopped (the team last in control has committed a violation), the clock resets to 30, and the ring goes to the other team in the nearest circle in the zone where the ring was last contacted or controlled. A goaltender ring may replace a defensive free pass.
• Error at zero. If the signal sounds in error, play is stopped, the clock is reset to 30 and the ring is awarded to the team last in control. If the clock is reset in error, play continues.
• End of period. Turn the display off when less time remains in the period than on the shot clock.
• Timeouts. The shot clock operator can start the 30-second clock to time a team timeout.