In Jainism, “period cycle” usually means Kāl‑chakra – the wheel of Time.

I’ll explain it in very simple points.

---

1. Time is beginningless and endless

• Time has no start and no end.
• It keeps moving in repeating cycles, like a wheel going round and round.
• Each full cycle is called Kāl‑chakra (time cycle / time‑wheel).

You can read a simple overview here

---

2. Two halves of each time cycle

Every full time cycle has two equal halves:

1. Utsarpiṇī – ascending / progressing half

- Conditions of the world improve slowly. - Height, age, strength, happiness, values, religion – all increase.

1. Avasarpiṇī – descending / declining half

- Conditions of the world become worse slowly. - Height, age, strength, happiness, values, religion – all decrease.

After one full Utsarpiṇī + Avasarpiṇī, the same pattern repeats again, endlessly.

---

3. Six eras (Ārās) in each half

Both halves (Utsarpiṇī and Avasarpiṇī) are divided into 6 eras (ārā). Names are same, but direction is opposite:

1. Sukhama‑sukhama – only happiness (very good)
2. Sukhama – mostly happiness (good)
3. Sukhama‑dukhama – more happiness, some sorrow
4. Dukhama‑sukhama – more sorrow, some happiness
5. Dukhama – mostly sorrow (bad)
6. Dukhama‑dukhama – only sorrow (very bad)

• In Utsarpiṇī: it starts from very bad and goes to very good.
• In Avasarpiṇī: it starts from very good and goes to very bad.

So, over time:

• One half = step‑by‑step rise.
• Next half = step‑by‑step fall.

Then again rise, then fall… forever.

Simple list of the 6 eras:

---

4. Where are we now?

According to Jain tradition:

• We are in Avasarpiṇī (the descending half).
• In that, we are in the 5th era – Dukhama (sorrow‑dominant period).
• This 5th era lasts 21,000 years in total; around 2,500 years are over, a lot is still remaining.

More detail:

---

5. Tirthankars and the time cycle

• In every half‑cycle (each Utsarpiṇī and each Avasarpiṇī), there are 24 Tirthankars.
• Our 24th Tirthankar, Bhagwān Mahāvīr, came in this current Avasarpiṇī, in the earlier, better eras than now.

This repeats every Utsarpiṇī and every Avasarpiṇī – 24 Tirthankars in each.

Overview connected with history of Jainism:

---

6. Digambar & Shvetambar views

• Both traditions agree on:

- Time is eternal and cyclic. - Each cycle has Utsarpiṇī and Avasarpiṇī. - Each half has six eras. - 24 Tirthankars appear in every half‑cycle.

• They may differ slightly in:

- Exact counting of years. - Some historical dates (like the exact year of Mahāvīr’s nirvāṇa).

But the basic structure of the time cycle is same in both.

---

If you want, next step can be a very short “story‑style” explanation of how people live in each of the 6 eras.