According to Jainism, time is divided into endless cycles, each consisting of two halves: Utsarpini (ascending) and Avasarpini (descending). We are currently in the fifth era (pancham kaal) of the Avasarpini (descending) half, which is considered as the "Kali Yuga" or the age of sorrow, degeneration, and spiritual decline.

Jain scriptures describe that the current era, pancham kaal, is characterized by the absence of Tirthankaras, reduced spiritual values, and increased suffering. This era will last for 21,000 years according to Jain tradition (the length may vary in different texts). After this, the sixth era (chhath kaal) will begin, which is even worse, marked by extreme misery, natural calamities, and very short human lifespans. This period will last for 21,000 years as well.

After the end of the sixth era, the cycle will begin to ascend again (Utsarpini), starting with the first era, which will gradually bring improvement in spiritual and moral standards.

In summary: According to Jainism, the "Kalyug" (pancham kaal) will end after 21,000 years, followed by a worst period (chhath kaal) of another 21,000 years. After this, the ascending half of time begins, leading to gradual improvement.

There is no concept of a sudden "end" of Kalyug in Jainism, but rather a gradual transition as part of the endless cosmic time cycles.