Where the calculation is for the purposes of section 88 or 89, the calculation date is the day immediately preceding the first day of the period of notice required by section 86(1) or (2).
Where the calculation is for the purposes of section 93, 117 or 125, the calculation date is—
Where the calculation is for the purposes of section 112, 119, 120 , 121 or 124 , the calculation date is—
Where the calculation is for the purposes of section 147(2), the calculation date is the day immediately preceding the first of the four, or six, weeks referred to in section 148(2).
Where the calculation is for the purposes of section 162, the calculation date is—
The date referred to in subsections (3)(c) and (5)(c) is the date on which notice would have been given had—
(whether or not those conditions were in fact fulfilled).