In Jain Dharma, “aras” (the six eras of time) are accepted on the basis of śruti (Āgams), Jain cosmology, and the teachings of Tirthankars, not on modern scientific measurement.

Here is the kind of “evidence” Jain tradition gives:

1. Scriptural evidence (Āgamic pramāṇ)

- Jain scriptures describe: - Time as beginning‑less and endless (anādi‑ananta kāl). - Each time‑cycle (kālacakra) having two halves: Utsarpiṇī (ascending, things improve) and Avasarpiṇī (descending, things decline). - Each half is divided into six unequal eras = six “ārās” with clear names and characteristics (sukhma‑sukhma, sukhma, etc.). - Both Śvetāmbara and Digambara accept this 6‑ārā structure; details like exact durations may differ, but the existence of aras does not.

You can see a simple explanation of the time‑cycle and six aras here

1. Logical / doctrinal evidence inside Jainism

- Cyclicity of saṃsār: If karmas and births have no beginning, then a repeating pattern of rise and fall is more consistent than a straight line with a first starting point. - Appearance of Tirthankars: Jain texts give: - fixed numbers of Tirthankars in each half‑cycle, - their names, parents, places, and time‑eras. This whole framework only makes sense inside the 6‑ārā time‑model. - Gradual decline we observe: From a Jain point of view, the visible decline in: - human life‑span, - physical strength, - moral standards, is seen as matching the description of 5th ārā (duḥṣamā kāl / pancham kāl) in Avasarpiṇī.

1. Type of evidence you should expect

- Jainism does not claim “laboratory proof” of aras. - It presents them as: - revealed by Sarvajña Tirthankars (omniscient beings), - systematized in Jain cosmology, - internally consistent with karma‑theory and the history of Tirthankars. - So, for a Jain, faith plus reasoning based on Tirthankar‑vachan is the evidence; for a scientist, this will be metaphysical, not empirical.

1. Current era according to Jain Dharma

- We are said to be in the 5th ārā of Avasarpiṇī, a sorrow‑dominated time (duḥṣamā / pancham kāl), lasting 21,000 years in total. More details here

In summary: Within Jain Dharma, the “evidence” for aras is scriptural revelation and cosmological reasoning based on the teachings of Kevalī Bhagwāns, not modern experimental proof.