You searched for: “anno mundi
anno mundi (s) (noun) (no plural)
In the year of the world: Anno mundi is a term for reckoning the passage of time from a fixed event.

Anno mundi, abbreviated A.M., marks the number of years that have passed since the world began. In the Hebrew tradition, the year of creation corresponds to 3761 B.C.

The Irish theologian, Ussher, in the mid-seventeenth century computed the date of creation as 4004 B.C.; therefore, the year A.D. 2000 corresponds to 5761 A.M. or 6004 A.M., depending on whose date of creation one might prefer.