A declared public health emergency—
(a) starts when it is declared under section 319 (2) ; and
(b) unless either of the following happens, ends 7 days after the day it is declared—(i) the Minister sooner ends the declared public health emergency under section 324 (1) ;(ii) a regulation extends, under section 323 , the period of the declared public health emergency beyond the end of the 7 days.