English: The binary in the center has an orbital period of 7.94 years and each time at the periastron the dust production of the collision-wind binary increases. I counted about 20 "shells" and because each ring is about 7.94 years apart, you can say that the entire nebula was created in about 160 years.
The star is 6064.6 light-years distant (Gaia DR3) and the last time we saw the periastron passage was around 2017. So the innermost shell should have formed 4048 BC and the outermost shell should have formed around 4206 BC.