Yes. In Jain usage, Poonam tithi and Purnima tithi generally mean the same lunar day — the full moon day.

• Purnima is the Sanskrit/Hindi term for the full moon tithi.
• Poonam is the common spoken form used in many Indian languages, especially Gujarati and Hindi.

In Jain calendars and observances, this tithi is often important for fasting, vows, and religious functions.