No Jesus cannot come back at any time. The first time He was here, He fulfilled the Spring Feasts of the Lord (Leviticus 23). He died on Passover, arose from the grave on the Feast of First Fruits and poured out the Holy Spirit on the Feast of Shavuot (Pentecost). If He did that for the Spring Feasts then there is no reason He won't do that again for the Fall Feasts.