What is the due date to file my 2024 tax returns for my LLC Partnership in state of PA?

For a calendar-year filer, file the current tax year PA-20S/ PA-65 Information Return and PA-20S/PA-65 Schedules RK-1 and NRK-1 on or before April 15, 2025, including an extension date of Sept. 15, 2025. 

For a fiscal-year filer, file the current tax year PA-20S/PA-65 Information Return and PA-20S/PA-65 Schedules RK-1 and NRK-1 on or before the 15th day of the fourth month following the close of the fiscal year including an extension date of five months after the original due date. If the due date falls on a Saturday, Sunday or business holiday, the entity must file the PA-20S/PA-65 Information Return no later than midnight on the first business day following the Saturday, Sunday or business holiday. The U.S. Postal Service postmark date on the envelope is proof of timely filing

2024 PA-20S/PA-65 - PA S Corporation/Partnership - Information Return (pg. 13)