UK Parliament — House of Commons

the House shall not be counted between a quarter-past one and a quarter-past two o'clock; but if during that period it shall appear on a division that forty Members are not present, the next business shall be taken.

Paragraph (1) of this standing order shall apply to sittings on Fridays, with the substitution of references to a quarter-past one and a quarter-past two of the clock for the references to half-past seven and half-past eight of the clock.