Avsarpini Kal and Utsarpini Kal are the two main halves of time in Jain cosmology.

• Utsarpini Kal (the ascending half):

- This is the period when the world and beings gradually rise in virtue and lifespan. - People live longer, moral qualities are higher, and spiritual practice tends to be easier. - It is followed by a transition that leads into the Avsarpini Kal.

• Avsarpini Kal (the descending half):

- This is the period when the world and beings decline in virtue and lifespan. - People tend to live shorter lives, and moral conditions become more challenging. - It ends after a sequence of changes that eventually leads back to the next Utsarpini Kal, continuing the cycle.

Both terms describe cyclic phases of time. There are varying descriptions and details in Digambar and Shvetambar traditions about the exact nature of each phase and the sequence of events within them, but the overarching idea is that time moves in alternating eras of rising and declining spiritual quality.

If you’d like, I can share concise references from Jain scriptures that illustrate how these two halves are described in each tradition.