Here is a simple clarity:

• Paryushan (Śvetāmbara) / Das‑Lakshan (Digambara)

- A yearly spiritual festival focused on repentance, self‑discipline, svādhyāy (scriptural study), fasting, pratikraman, and universal forgiveness (Micchāmi Dukkaḍaṁ). - Śvetāmbara: 8 days, ending with Samvatsari (the great day of forgiveness). - Digambara: 10 days (Das‑Lakshan), each day devoted to one supreme virtue, ending with Kshamāvaṇī (forgiveness).

• Mahavir Jayanti (Mahavir Janma Kalyānak)

- The celebration of Bhagwān Mahāvīr’s birth, observed on Chaitra Shukla Trayodashi (March/April by the lunar calendar). - It is a separate festival from Paryushan.

• Why people connect them

- In the Śvetāmbara tradition, during Paryushan the Kalpasūtra is publicly read. On the 5th day (Pañchamī), the Janma‑Vañchan (reading of Mahāvīr’s birth episode) is performed with devotion. This is not Mahavir Jayanti; it is the reverent reading of his Janma‑Kalyānak within Paryushan to inspire sādhanā.

Essence preserved (both traditions):

• Paryushan/Das‑Lakshan: purification of karma, vows, restraint, forgiveness.
• Mahavir Jayanti: remembrance of the Tīrthaṅkar’s birth and virtues, strengthening right faith, knowledge, and conduct.

For simple, authentic explanations:

• What is Paryushan?
• Why Janma‑Vañchan on the 5th day of Paryushan?