31 CFR 551.305: Effective date.

(a) The term effective date refers to the effective date of the applicable prohibitions and directives contained in this part as follows:

(1) With respect to a person listed in the Annex to E.O. 13536, as amended by E.O. 13620, 12:01 a.m. eastern daylight time, April 13, 2010;

(2) With respect to a person whose property and interests in property are otherwise blocked pursuant to § 551.201, the earlier of the date of actual or constructive notice that such person's property and interests in property are blocked; and

(3) With respect to the prohibition set forth in § 551.207, 2:00 p.m. eastern daylight time, July 20, 2012.

(b) For the purposes of this section, constructive notice is the date that a notice of the blocking of the relevant person's property and interests in property is published in the Federal Register.