Jesus said He would return just as He left. He died on Friday and was resurrected Sunday. Jesus died on the cross April 1, 33 AD Friday (Gregorian) which is April 3, 33 AD Friday (Julian).

On the 40th day from His resurrection, He was raised up on Thursday, May 14, 33 AD (Julian).

Pentecost was on the 50th day Sunday May 24, 33 AD (Julian).

If Jesus returns just as He left would He return on Thursday or Sunday? I believe He would return on Sunday because that's when He left. The 40th days of His resurrected bodily is technically not when He left. He died on Friday, but left His body of flesh and blood in the grave on Sunday. On Thursday, He was still with us really giving us the Holy Spirit 10 days later on the 50th day on Sunday.

So Jesus must return on a Sunday.

Tisha B'Av, Day of Atonement and Tabernacles never land on a Sunday. Why?