In Jainism, the doctrine of the Tirthankaras is eternal and timeless—Jain texts describe a succession of enlightened teachers who appear in different cosmic eras. Historically and chronologically, most Jain traditions place the most recent and well-attested teacher Mahavira (the 24th Tirthankara) around the 6th century BCE.

• Mahavira: birth around 599 BCE, attained moksha (nirvana) around 527 BCE.
• The tradition also honors Parshvanath (the 23rd Tirthankara) as the immediate predecessor, who is dated earlier (often placed several centuries before Mahavira, with variations in exact years among Digambar and Śvetambar sources).

So:

• Eternal truth/teaching of Jainism: timeless.
• As a historical movement with named teachers: roughly 6th century BCE for Mahavira’s life.