WP 9.1 The duties of the timekeepers shall be:
(a) to record the exact periods of actual play, timeouts and the intervals between the periods;
(b) to record the periods of continuous possession of the ball by each team;
(c) to record the exclusion times of players ordered from the water in accordance with the Rules, together with the re-entry times of such players or their substitutes;
(d) to audibly announce the start of the last minute of the game and of the last minute of the second period of any extra time;
(e) to signal by whistle after 45 seconds and at the end of each timeout.
WP 9.2 A timekeeper shall signal by whistle (or by any other means provided it is distinctive, acoustically efficient and readily understood), the end of each period independently of the referees and the signal shall take immediate effect except:
(a) in the case of the simultaneous award by a referee of a penalty throw, in which event the penalty throw shall be taken in accordance with the Rules;
(b) if the ball is in flight and crosses the goal line, in which event any resultant goal shall be allowed.