The 22 days allocated in each calendar year for the House of Commons to consider the business of supply are divided as follows:
Of these 22 days, no more than one-fifth may fall on a Wednesday, and no more than one-fifth on a Friday (the shortest sitting days of the week).
If, for any reason, the number of sitting days in any supply period is lower than the number prescribed under the parliamentary calendar, the number of allotted days in that period is reduced in proportion to the number of sitting days the House stood adjourned. The Speaker will determine and announce to the House any reduction in the number of allotted days.
Should the House sit more than the prescribed number of sitting days, the total number of allotted days will be increased by one day for every five additional days the House sits.
Unused days from the six days allotted to the debate on the Address in Reply to the Speech from the Throne or from the four days allotted to the budget debate may be added to the number of allotted days in the supply period in which they would have been taken up.
If, in the supply period ending June 23, the government seeks approval for supplementary estimates for the previous fiscal year (also referred to as final supplementary estimates), a further three sitting days will be allocated in that period for their consideration and for the passage at all stages of the related supply bill.
In a normal supply cycle, concurrence motions are dealt with as follows:
A provisional change, in place for the remainder of the Forty-Second Parliament, was adopted by the House in June 2017 to replace the interim supply process with interim estimates. Interim estimates are treated in the same manner as other estimates, including being tabled and deemed referred to committee. The interim estimates are also considered during the supply period ending March 26.