(1) A unitrust policy must provide the period used under ss. 738.306 and 738.307. The period must be the calendar year.
(2) A unitrust policy may provide standards for:
(a) Using fewer preceding periods under s. 738.306(1)(b)1. or (2)(a) or (b) if:
1. The trust was not in existence in a preceding period; or
2. Market indices or other published data are not available for a preceding period;
(b) Using fewer preceding periods under s. 738.307(2)(e) if:
1. The trust was not in existence in a preceding period; or
2. Fair market values are not available for a preceding period; and
(c) Prorating a unitrust amount on a daily basis for a part of a period in which the trust or the administration of the trust as a unitrust or the interest of any beneficiary commences or terminates.