According to Jainism, Tirthankaras are born in the "utsarpini" (ascending) and "avasarpini" (descending) halves of the time cycle (kālchakra). Specifically, in the current avasarpini (descending cycle), it is said that 24 Tirthankaras appear. Similarly, in the utsarpini (ascending cycle), 24 Tirthankaras will also appear.

Thus, Tirthankaras are born in both halves of the time cycle, but only during specific periods when conditions are suitable for spiritual progress and liberation.