Bhadarva Sud Punam is a Jain calendrical date meaning:

• Bhadarva (Bhadrapada) is a lunar month in the Jain calendar.
• Sud (often used to denote the bright half) or sometimes just “Sud” is used in the month’s dating terminology.
• Punam means the full moon day.

So, Bhadarva Sud Punam = the full Moon day in the Bhadrapada month. The exact religious observances on this date can differ slightly between Digambar and Śvetāmbara communities, but it is typically observed as a significant lunar-day date in the Jain cycle and may be linked to particular Pratikraman or vows in some local traditions.