Here are the Jain holidays / kalyanaks I could verify for May 2026:

• May 8, 2026 — Shri Shreyanshnath Chyavan Kalyanak ( jaincenternj.org)
• May 10, 2026 — Shri Munisuvrat Swami Janma Kalyanak ( jaincenternj.org)
• May 11, 2026 — Shri Munisuvrat Swami Moksha Kalyanak ( jaincenternj.org)
• May 14, 2026 — Shri Shantinath Janma Kalyanak and Shri Shantinath Moksha Kalyanak ( jaincenternj.org)
• May 15, 2026 — Shri Shantinath Diksha Kalyanak ( jaincenternj.org)
• May 19, 2026 — Akshaya Tritiya / Varsitap Parna (Akhatrij), an important Jain observance connected with Lord Rishabhdev’s fast-breaking. ( festivaldays.in)

From the Jain Center of Southern California calendar, May 2026 also includes Shri Gautamswami Kalyanak Puja / Ekasana and JCSC Jinalay Anniversary celebrations during the month, though the snippet I could verify does not show the exact Gregorian dates for those items. ( jaincenter.org)

If you want, I can also turn this into a clean date-wise May 2026 Jain calendar list.