In Jainism there isn’t a standard set of “21 muharats” for pooja. Muhurat timings are a feature of some Hindu calendars and are not a fixed part of Jain ritual practice. Jain puja and devotional activities are typically flexible and can be performed at a suitable time of the day, with emphasis on sincerity, purification, and Right Faith (Samyak Darshan).

If you had a specific Jain ritual or festival in mind (for example, a samayik, puja for Mahavir, or a particular tirthankara’s worship) I can explain the customary conduct and what time frames are usually favored in Jain communities for that practice.