under this subparagraph with respect to a contributor during a calendar year, the political committee receives additional contributions from that contributor during that year, the committee shall submit an additional notification under clause (i) with respect to such contributor each time the aggregate amount of the additional contributions received from the contributor during the year equals or exceeds $1,000 (excluding the amount of any contribution for which information is required to be included in a previous notification under this subparagraph). (iii) The political committee shall submit the notification required under this subparagraph with respect to a contributor— (I) in the case of a notification described in clause (i), not later than 48 hours after the date on which the aggregate amount of contributions received from the contributor during the calendar year first equals or exceeds $1,000