72 Pa. Stat. § 3653
It shall be the duty of the commissioners of the sinking fund, on the first business day of each month, to prepare a statement of the total amount of money in said fund, which, having been verified by oath or affirmation, shall be published in two newspapers in Harrisburg for public information. The commissioners of the sinking fund shall also on the first business day in the months of May, August, November and February, in each and every year hereafter, apply all the moneys in the sinking fund to the redemption of an equivalent amount of the public debt. They shall forthwith give local notice of the amount of said debt which they are prepared to redeem, that the said amount will be redeemed on presentation to the designated disbursing agent of the state, and that the interest upon the certificates thereof shall cease from and after a day certain, to be designated by them, not more than ninety days after the publication of said notice: Provided, That the loans of the commonwealth shall be redeemed, as far as practicable, in the order of their maturity.
72 P.S. § 3653