Law 16 (Start of play; cessation of play)
1. Call of Play
The umpire at the bowler's end shall call Play at the start of the match and on the resumption of play after any interval or interruption.

2. Call of Time
The umpire at the bowler's end shall call Time on the cessation of play before any interval or interruption of play and at the conclusion of the match. See Law 27 (Appeals).

3. Removal of bails
After the call of Time, the bails shall be removed from both wickets.

4. Starting a new over
Another over shall always be started at any time during the match, unless an interval is to be taken in the circumstances set out in 5 below, if the umpire, after walking at his normal pace, has arrived at his position behind the stumps at the bowler's end before the time agreed for the next interval, or for the close of play, has been reached.

5. Completion of an over
Other than at the end of the match,
(a) if the agreed time for an interval is reached during an over, the over shall be completed before the interval is taken except as provided for in (b) below.

(b) when less than 2 minutes remain before the time agreed for the next interval, the interval will be taken immediately if
either (i) a batsman is out or retires
or (ii) the players have occasion to leave the field
whether this occurs during an over or at the end of an over. Except at the end of an innings, if an over is thus interrupted it shall be completed on resumption of play.

6. Last hour of match – number of overs
When one hour of playing time of the match remains, according to the agreed hours of play, the over in progress shall be completed. The next over shall be the first of a minimum of 20 overs which must be bowled, provided that a result is not reached earlier and provided that there is no interval or interruption in play.
The umpire at the bowler's end shall indicate the commencement of this 20 overs to the players and the scorers. The period of play thereafter shall be referred to as the last hour, whatever its actual duration.

7. Last hour of match – interruptions of play
If there is an interruption in play during the last hour of the match, the minimum number of overs to be bowled shall be reduced from 20 as follows.
(a) The time lost for an interruption is counted from the call of Time until the time for resumption of play as decided by the umpires.

(b) One over shall be deducted for every complete 3 minutes of time lost.

(c) In the case of more than one such interruption, the minutes lost shall not be aggregated; the calculation shall be made for each interruption separately.

(d) If, when one hour of playing time remains, an interruption is already in progress,
(i) only the time lost after this moment shall be counted in the calculation;
(ii) the over in progress at the start of the interruption shall be completed on resumption of play and shall not count as one of the minimum number of overs to be bowled.

(e) If, after the start of the last hour, an interruption occurs during an over, the over shall be completed on resumption of play. The two part-overs shall between them count as one over of the minimum number to be bowled.

8. Last hour of match – intervals between innings
If an innings ends so that a new innings is to be started during the last hour of the match, the interval starts with the end of the innings and is to end 10 minutes later.
(a) If this interval is already in progress at the start of the last hour, then to determine the number of overs to be bowled in the new innings, calculations are to be made as set out in 7 above.

(b) If the innings ends after the last hour has started, two calculations are to be made, as set out in (c) and (d) below. The greater of the numbers yielded by these two calculations is to be the minimum number of overs to be bowled in the new innings.

(c) Calculation based on overs remaining.
(i) At the conclusion of the innings, the number of overs that remain to be bowled, of the minimum in the last hour, to be noted.
(ii) If this is not a whole number it is to be rounded up to the next whole number.
(iii) Three overs to be deducted from the result for the interval.

(d) Calculation based on time remaining.
(i) At the conclusion of the innings, the time remaining until the agreed time for close of play to be noted.
(ii) Ten minutes to be deducted from this time, for the interval, to determine the playing time remaining.
(iii) A calculation to be made of one over for every complete 3 minutes of the playing time remaining, plus one more over for any further part of 3 minutes remaining.

9. Conclusion of match
The match is concluded
(a) as soon as a result, as defined in sections 1, 2, 3 or 4 of Law 21 (The result), is reached.

(b) as soon as both
(i) the minimum number of overs for the last hour are completed
and (ii) the agreed time for close of play is reached
unless a result has been reached earlier.

(c) if, without the match being concluded either as in (a) or in (b) above, the players leave the field, either for adverse conditions of ground, weather or light, or in exceptional circumstances, and no further play is possible thereafter.

10. Completion of last over of match
The over in progress at the close of play on the final day shall be completed unless
either (i) a result has been reached
or (ii) the players have occasion to leave the field. In this case there shall be no resumption of play, except in the circumstances of Law 21.9 (Mistakes in scoring), and the match shall be at an end.

11. Bowler unable to complete an over during last hour of match
If, for any reason, a bowler is unable to complete an over during the last hour, Law 22.8 (Bowler incapacitated or suspended during an over) shall apply.