5. Presentation for registration---Regulation 15 of the principal regulations is hereby amended by omitting the words ``between the hours of 9 a.m. and 0.30 p.m. or between the hours of 1.30 p.m. and 3 p.m.'', and substituting the words ``on a day when the office is required by regulation 3 (1) of these regulations to be open and at a time when it is required by regulation 4 of these regulations to be open''.