The English phrase appointed feasts
is derived from a Hebrew noun root meaning to appoint
or to designate.
In the present context it refers to specific times that the Lord has set in the Hebrew calendar. In other words, it is a technical phrase relating to religious festivals throughout the year (see Exodus 13:10; Exodus 23:15; Exodus 34:18).
2 Parle aux enfants d'Israël, et tu leur diras: Les fêtes de l'Eternel, que vous publierez, seront de saintes convocations. Voici quelles sont mes fêtes.