Here are the main Jain celebrations and the approximate time of year they occur. The exact dates vary each year because they are set by the lunar calendar, and there are small differences between Digambar and Shwetambar traditions.

• Mahavir Jayanti

- What it is: Birth anniversary of Lord Mahavira, the 24th Tirthankara. - When: in spring, usually around March–April (Chaitra month in the lunar calendar). The exact date changes every year.

• Paryushan Parva

- What it is: A major period of fasting, reflection, and self-purification; the length and rituals differ by tradition. - When: in late monsoon/early autumn, typically around August–September (depending on the lunar calendar). Shwetambar practice often lasts about 10 days; Digambar practice may be 8 days.

• Samvatsari (the forgiveness day)

- What it is: The last day of Paryushan; a day for seeking and granting forgiveness. - When: coincides with the final day of Paryushan, so the date is the same year-to-year as Paryushan ends.

• Jain Diwali (Nirvan/Deepawali)

- What it is: Celebration associated with Mahavira’s Nirvana (and, in some regions, other events in Jain tradition). It is observed with lamps, prayers, and remembrance. - When: in autumn, around the Kartik month (often a few days after the Hindu Diwali, dates vary by year).

Notes on differences:

• The order, length, and emphasis of these festivals can differ between Digambar and Shwetambar communities. For example, the number of days for Paryushan and some ritual practices may vary between the two traditions.
• All dates are lunar and shift yearly; to know the exact date for a specific year, you would check the Jain calendar for that year.

If you’d like, I can look up the exact dates for a particular year you have in mind and provide the precise days for Mahavir Jayanti, Paryushan, Samvatsari, and Diwali as observed by Digambar and Shwetambar communities.