What law shall govern the imposition of the donor's tax?

The donor’s tax shall not apply unless and until there is a completed gift. The transfer of property by gift is perfected from the moment the donor knows of the acceptance by the donee; it is completed by the delivery, either actually or constructively, of the donated property to the donee. Thus, the law in force at the time of the perfection/completion of the donation shall govern the imposition of the donor’s tax. [Sec 11, RR 2-2003]