Oregon Revised Statutes Public Financial Administration § 291.342

(1) By August 15 of each year, but not earlier than 90 days from the end of the regular session of the Legislative Assembly held in that calendar year, the Oregon Department of Administrative Services, with the assistance of the Department of Revenue, shall:

(2) In addition to the requirement in subsection (1) of this section, the Oregon Department of Administrative Services with the assistance of the Department of Revenue shall for each calendar quarter of the year ascertain by computation and estimate the total amount of revenue available for state purposes for the current fiscal year, as well as the amount of revenue received quarterly, cumulated throughout the biennium, and report its estimate to the Legislative Revenue Officer and to the Legislative Fiscal Officer.

(3) In carrying out its duties under subsection (2) of this section, the Oregon Department of Administrative Services shall issue quarterly a statement setting forth the methodology and assumptions used in making the revenue estimate. Nothing in this subsection requires the statement to set forth procedures used or methods used to determine either the methodology or the assumptions.