For over forty years I have been watching for the Lord´s return. I have seen many calculations based on various dates, none of which panned out. Most of these dates were based on events in Jewish history, holidays etc. 

I decided to start with Daniel´s 70 weeks:

24Seventy weeks are decreed for your people and your holy city: to finish the transgression, to put an end to sin, and to atone for iniquity, to bring in everlasting righteousness, to seal both vision and prophet, and to anoint a most holy place.

25Know therefore and understand: from the time that the word went out to restore and rebuild Jerusalem until the time of an anointed prince, there shall be seven weeks; and for sixty-two weeks it shall be built again with streets and moat, but in a troubled time.

26After the sixty-two weeks, an anointed one shall be cut off and shall have nothing, and the troops of the prince who is to come shall destroy the city and the sanctuary. Its end shall come with a flood, and to the end there shall be war. Desolations are decreed.

27He shall make a strong covenant with many for one week, and for half of the week he shall make sacrifice and offering cease; and in their place shall be an abomination that desolates, until the decreed end is poured out upon the desolator.

— Daniel 9:24–27 (NRSV)

April 6 ad32 has been calculated as the date that the Messiah was cut off. I would think that He was cut off in the middle of a seven (7 years or one week of years) which would indicate that He had ministered for three and one half years. If you go back 3 1/2 (360 day Jewish year) years from April 6, 0032 you get to October 24 0028. I believe that this may be the date that Christ's ministry started.  Could this have been His birthday?

October 24, 0028 would have been when the Jews first heard the Messiah preach. He was rejected and I believe that the Jews were punished for 2000 years from when they first heard the Messiah preach. If we go forward two thousand years from that date you get to October 24 2028. A possible day for the second coming. If you go back 2520 days (7 Jewish years) you get to November 30. 2021 (Hanukah starts November 29 in 2021), If you go back 360 days from November 30, 2021 you get to December 5, 2020. The reason to go back eight years is that I believe that we may be hidden for eight years rather than seven ( Jews celebrate an eighth day of Sukkot and Hanukkah is eight days.) December 5, 2020 is the 19th of Kislev. This date is known as the "Rosh Hashanah of Chassidism". 

We, of course, won't know until we know.

                                                                                                                                  Karl R