Answer

In Jain tradition, the exact historical time-period of every Tirthankar’s life or reign is not known in the modern historical sense.

However, Jain scriptures do give traditional descriptions of:

• Each Tirthankar’s lifespan
• Their height
• Their era within the time-cycle
• The period between some Tirthankars
• Their spiritual role in the decline of the present half-cycle of time

The “gap” between Tirthankars is not uniform. It becomes smaller as time moves downward in the present Avasarpiṇī — the descending half-cycle of time.

Explanation

Jain Dharma explains time as beginningless and endless, moving in two great cycles:

• Utsarpiṇī — ascending time-cycle
• Avasarpiṇī — descending time-cycle

In each half-cycle, 24 Tirthankars appear. The current 24 Tirthankars belong to the present Avasarpiṇī.

The first Tirthankar, Bhagwan Rishabhdev, appeared in a very ancient era when human lifespan, body size, and spiritual capacity were much greater. As time declined, the gaps between later Tirthankars became shorter.

The last two Tirthankars are closer to historically understandable time:

• Bhagwan Parshvanath — traditionally placed about 250 years before Bhagwan Mahavir
• Bhagwan Mahavir — the 24th Tirthankar, whose life is the most historically discussed among the Tirthankars

But for the earlier Tirthankars, the time periods are described in extremely vast traditional Jain units such as pūrva, sāgaropama, and palyopama. These are not ordinary historical calendar years.

Do We Know Their Exact Reign?

If by “reign” you mean political rule as kings, then not every Tirthankar is remembered mainly as a ruler. Some were born as princes or kings before renunciation, but their real importance is not political rule — it is their role as Tirthankars, the founders of the fourfold Jain Sangh.

If by “reign” you mean the period of their spiritual teaching after attaining Keval Jñān, Jain tradition gives lifespans and important life events, but exact dates in modern historical chronology are generally not available for most Tirthankars.

Traditional Understanding

Jain tradition preserves the order of the 24 Tirthankars as:

1. Rishabhdev
2. Ajitnath
3. Sambhavnath
4. Abhinandannath
5. Sumatinath
6. Padmaprabhu
7. Suparshvanath
8. Chandraprabhu
9. Pushpadant / Suvidhinath
10. Shitalnath
11. Shreyansnath
12. Vasupujya
13. Vimalnath
14. Anantnath
15. Dharmanath
16. Shantinath
17. Kunthunath
18. Aranath
19. Mallinath
20. Munisuvrat Swami
21. Naminath
22. Neminath
23. Parshvanath
24. Mahavir Swami

Among these, Jain tradition especially connects:

• Neminath with the era of Shri Krishna
• Parshvanath roughly 250 years before Mahavir
• Mahavir Swami with a historically closer and more documented period

Takeaway

The gaps between Tirthankars are known in Jain tradition through sacred cosmological time, but not as exact modern calendar dates for all 24 Tirthankars.

Their significance is not measured by political reign, but by their supreme spiritual achievement: they attained Keval Jñān, established the path of liberation, and showed the way to destroy karma and attain Moksha.