(a) (1) As used in this section, the terms "pecuniary disposition" and "transfer in trust of a pecuniary amount" mean, respectively, a disposition by will or a transfer under a trust agreement of a specific amount of money, which amount is either expressly stated in the instrument or determinable by means of a formula which is stated in the instrument.

(2) Whether a testamentary disposition or transfer in trust is pecuniary or fractional in character depends upon the intention of the creator.

(b) Unless the instrument expressly provides otherwise:

(1) Where a will or a trust agreement authorizes the executor or trustee (hereinafter called the "fiduciary") to satisfy wholly or partly in kind a pecuniary disposition or transfer in trust of a pecuniary amount, the assets selected by the fiduciary for that purpose shall be valued at their respective values on the dates of their distribution.

(2) Where a will or a trust agreement authorizes the fiduciary to satisfy wholly or partly in kind a pecuniary disposition or transfer in trust of a pecuniary amount and the instrument requires the fiduciary to value the assets selected by the fiduciary for such distribution as of a date other than the dates of their distribution, the assets selected by the fiduciary for that purpose, together with any cash distributed, shall have an aggregate value on the dates of their distribution amounting to no less than, and to the extent practicable no more than, the amount of such testamentary disposition or transfer in trust as stated in, or determined by the formula stated in, the instrument.

(c) This section applies to wills of decedents dying before, on or after its effective date and to trust agreements executed before, on or after such date, provided, however, that it shall not be applied so as to require repayment to the fiduciary of any distributions actually made prior to such date.