72 Pa. Stat. § 5572.6
In order to enable the taxpayer or owner having the right to redemption under a tax sale to receive the full benefits of this act, no real property shall be sold for nonpayment of taxes before August first, one thousand nine hundred and thirty-nine, and any tax sale shall be adjourned or readjourned or right of redemption extended as often as may be necessary for this purpose. If, in counties of the first class the receiver of taxes and in all other counties a county treasurer extends the date on which taxpayers may make their first installment payment and receive the benefits of the act, in such case no sale shall be held by such treasurer or receiver before the date of extension fixed by him; but in all counties, except counties of the first class, all properties upon which such delinquent taxes are due and owing and which are not being paid under the installment plan herein provided shall be sold by such treasurer within three months after such extended date. If any tax sale is adjourned or readjourned or right of redemption extended after advertisement or sale, no additional advertisement or notice shall be necessary for the adjourned or readjourned sale or right of redemption. No such adjournment or readjournment or redemption, failure to adverse, or hold any such tax sale, shall invalidate the lien of any tax due and unpaid or sale had subject to redemption, but the lien of all such taxes shall be fully preserved during the entire installment period herein provided for, if the taxpayer avails himself of the privileges or benefits of this act: Provided, however, That in every case where a taxpayer avails himself of the privileges or benefits of this act, the period during which payment of said unpaid delinquent taxes is postponed or continued under this act shall not be included in computing and determining whether or not any right of the tax assessing and levying authority has been barred or lost by reason of the provisions of any statute, now existing or hereafter enacted, limiting the right of the said tax levying and assessing authorities to file, preserve or maintain the lien of the said taxes.
72 P.S. § 5572.6