3. For the purposes of article 7 of the Brucellosis (Scotland) Order 2009 as amended by article 2 of this Order, after 1st April 2011, the first interval of 3 months commences—
(a)on the date of the submission of the sample of milk in March 2011; or
(b)where no sample of milk was submitted in March 2011, on 1st April 2011.