The court may, if, having regard to all the circumstances of the case, it considers it appropriate to do so, in a periodical payments order, direct that -

(a) the period in respect of which payments under the order are to be made begins on a specified date that is before the date of the order but after the date of the institution of the proceedings for the grant of the decree of dissolution,

(b) without prejudice to section 117(1)(c), any payments under the order in respect of the period before the date of the order be paid in one sum and before a specified date, and

(c) the civil partner making the payments referred to in paragraph (b) deduct a specified amount equal to any payment made by that civil partner to the other civil partner during the period between the making of the order for the grant of the decree of dissolution and the institution of the proceedings.