Whirl out and whirl in
Does anyone know what is the meaning of: Whirl out and whirl in in the following poem:
"Sho the Platonic Year
Whirls out new rigth and wrong,
Whirls in the old instead;
All men are dancers and their tread
Goes to the Barbarous clangour of a gong".
by the way if anyone knows a good translation in spanish for this poem, please let me know, thanks in advance