According to Jain cosmology, the 5th Aara (Pancham Kaal / Dusham Kaal) is 21,000 years long. About 2,500+ years have already been completed in it, but the exact count is traditionally given slightly differently in different Jain traditions.

In simple words: we are currently in the 5th Aara, and only a small part of it has passed so far.