Dear John & Doves:
Pastor Mark Biltz has informed us that "No one knows the day or the hour" is a euphemism for Rosh Hashanah. Just like in America when someone says happy turkey day they know it means happy thanksgiving.
I think that Jack Kelly is half right when he states "that the 2nd Coming is a much more likely fulfillment of Rosh Hashanah...." But since we are speaking of a euphemism to designate a particular day and not necessarily a literal description regarding the Second Coming, calculations can indeed be utilized with trust proportionate to their adherence to Scripture.
Proposed Rapture Window & Tribulation Time-line