Note 4 — Chapter VI · ON TOWARDS NORTH INDIA. DARADA. IMAGE OF MAITREYA BODHISATTVA.
James Legge translation
(4) Tushita is the fourth Devaloka, where all Bodhisattvas are reborn before finally appearing on earth as Buddha. Life lasts in Tushita 4000 years, but twenty-four hours there are equal to 400 years on earth. E. H., p. 152.