• Why they are on different days: In Jain tradition there are two major sects with slightly different calendars and practices. Śvetāmbara Jains observe Paryuṣaṇ for 8 days, ending with Samvatsarī (the Forgiveness Day). Digambar Jains observe a separate festival called Daśa‑lakṣaṇa Parva (Das Lakshan Parva) for 10 days, which starts the day after the Śvetāmbara Paryuṣaṇ ends. So, the two festivals run back-to-back but on different schedules, not on the same exact days. ( jainknowledge.com)

• What each festival emphasizes:

- Paryuṣaṇ (Śvetāmbara) is an 8-day period of intensified sadhana, discourses, fasting, and pratikraman, culminating in Kshamavani (forgiveness day). - Daśa‑lakṣaṇa Parva (Digambar) is a 10-day festival focused on the ten virtues, with daily reflection and a culminating act of forgiveness as well. ( jainknowledge.com)

• About the dates: since the Jain calendar is lunar and local sanghs adjust timings, the exact Gregorian dates can vary by community and year. In many recent years, Śvetāmbara Paryuṣaṇ ends first, followed a day or two later by Das Lakṣaṇa Parva for Digambar Jains; the common pattern is still “Śvetāmbara eight days, Digambar ten days starting after.” Always check your local temple or sangh for the precise dates. ( jainknowledge.com)

If you’d like, I can point you to a simple day-by-day outline for both traditions.