4.—(1) Any period after 31st December 2013 during which a person enjoyed a right to reside under the 2006 Regulations as a jobseeker is to be taken into account for the purposes of—
(a)determining the relevant period in relation to that person; and
(b)determining whether condition C in regulation 6(9) of the 2006 Regulations applies.
(2) But where calculation of the relevant period pursuant to paragraph (1)(a) would result in a negative balance, the relevant period is to be treated as though it were zero days.