Laws of Cricket 1947 Code (Second Edition) - Law 16
Law 16 - Declarations (more)
When the start of play is delayed by weather [Law 14] shall apply in accordance with the number of days' play remaining from the actual start of the match.
When the start of play is delayed by weather Laws [14] and [15] shall apply in accordance with the number of days' play remaining from the actual start of the match.
Reproduction of the Laws of Cricket is by kind permission of Marylebone Cricket Club