Laws of Cricket 1947 Code (Fourth Edition) - Law 18
The umpires shall call "Time", and at the same time remove the bails from both wickets, on the cessation of play before any arranged interval, at the end of each day's play, and at the conclusion of the match. An "Over" shall always be started if "Time" has not been reached, and shall be completed unless a batsman is "Out" or "Retires" within 2 minutes of the completion of any period of play, but the "Over" in progress at the close of play on the final day of a match shall be completed at the request of either captain, even if a wicket fall after "Time" has been reached.
Notes on Law 18
1. If, during the completion of the last over of any period of play, the players have occasion to leave the field, the umpires shall call "time". In the case of the last over of the match, there shall be no resumption of play and the match shall be at an end.
2. The last over before an interval or the close of play shall be started, provided the umpire standing at square leg, after walking at his normal pace, has arrived at his position behind the stumps at the bowler's end before time has been reached. This provision will apply if a batsman is "Out" off, or "Retires" after, the last ball of an over when less than two minutes remain for play at the conclusion of the match,
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