Answer

For Shantinath Bhagwan, there is not one universally fixed weekday like “Saturdays for Munisuvrat” across all Jain traditions. In a commonly used Jain tirthankar chart, Shantinath is remembered on his own kalyanak tithis—especially Jeth Vad 13 for birth/nirvan and Posh Sud 9 for Kevalgyan. ( jinalaya.com)

Explanation

One Jain reference lists Shantinath Bhagwan’s:

• Birth Day: Jeth Vad 13
• Diksha Day: Jeth Vad 14
• Keval Gyan Day: Posh Sud 9
• Nirvan Day: Jeth Vad 13 ( jinalaya.com)

Another Jain calendar summary also mentions “Shantinatha’s Birth and Moksa” and his renunciation on the related tithis, which shows that communities may present the same sacred events in slightly different calendar formats. ( jainworld.jainworld.com)

Spiritual Understanding

So for Shantinath, the focus is usually on his kalyanak tithis rather than a fixed day of the week. His very name represents shanti—peace—so remembrance of Shantinath is especially associated with inner calm, forgiveness, and restraint. ( jinalaya.com)

Takeaway

If you want the short answer: Shantinath = Jeth Vad 13 / Posh Sud 9 / Jeth Vad 14 in common Jain tithi listings. ( jinalaya.com)