For the purposes of subsection (1)—
where an act extends over a period, the reference to the date of the act is a reference to the last day of that period;
a failure to act shall be treated as done when it was decided on.
For the purposes of subsection (2), in the absence of evidence establishing the contrary an employer shall be taken to decide on a failure to act—
when he does an act inconsistent with doing the failed act, or
if he has done no such inconsistent act, when the period expires within which he might reasonably have been expected to do the failed act if it was to be done.
Section 292A (extension of time limits to facilitate conciliation before institution of proceedings) applies for the purposes of subsection (1)(a).