In Jain Dharma, time is seen as cyclical and vast, not as a single linear start-to-end story. Here are the key Jain ideas that address your questions:

• Time cycles (kālchakra): The universe undergoes repeated rising and declinings of moral/spiritual conditions. This is not a one-time creation or a final end, but an endless sequence of cycles.

• Utsar and Avsar: Each cycle has periods of relative spiritual ascent (utsar) and relative spiritual decline (avsar). During avsar, moral and religious life tends to wane and beings accumulate karma in ways that make spiritual progress harder. The utsar periods are when dharma, merit, and spiritual opportunity tend to rise again.

• No universal “reset” like a big bang: There isn’t a single moment where the entire universe is wiped clean and everything starts over from scratch in the Jain view. Rather, there are dissolutions or pralayas of certain realms or components of the cosmos, guided by karmic laws, and then a new phase or cycle gradually unfolds. This is not a dramatic reset of all eras at once.

• Role of Tirthankaras: In each cycle, enlightened beings called Tirthankaras appear at appropriate times to restore dharma, teach pure conduct, and guide beings toward liberation. Their descent marks renewal within the cycle.

• Differences between traditions: There are nuanced differences in how Digambar and Shwetambar Jain traditions describe specific eras and the sequence of events within a cycle. The broad idea, however, remains: time is cyclical, there is continual moral rise and decline, and a “reset” in the sense of a new righteous guidance through a Tirthankar occurs within each cycle rather than a single universal wipe.

If you’d like, I can share concise verses or explanations from Jain scriptures that sketch this cyclical time concept (and note where Digambar and Shwetambar viewpoints differ).