Who says? He's coming to call His bride to Him. It's exactly what happens in the ancient Jewish wedding. When the father thinks all is ready he sends his son to get his bride ("only the father knows the day and the hour). The bride and the groom then spend 7 days secluded. At the end of that seven days the bride and groom then emerge and wedding feast is held.
Greater minds than ours have argued this for centuries. It doesn’t matter when He comes but that He comes ... all else takes away from His returning.