In Jainism there is no fixed universal duration for the last pratikraman. The length depends on the practitioner, the community tradition (Digambar vs. Shwetambar), and how many misdeeds and samyam/vratas one uses in confession and forgiveness during that session.

• Typical daily pratikraman: roughly 45 minutes to 1.5 hours, depending on how many prashodh and pratikraman chants one includes.
• Last pratikraman of a festival like Paryushan: often longer, sometimes 1.5 to 3 hours, because it may involve more detailed confession, reflective vrat discussions, and additional prayers.

If you want a precise duration for your setup, ask your guru or local temple group, as they usually follow a customary length for their community.