Fact is, the Greek word translated as "earthquake" is out of context. "Tremors" or "agitations" can apply to a tempest or storm as much as an earthquake and the context of "tremors" is related to people. That is an increase in the unrest or agitation of people during the last days in connection with the food shortages and pestilence. So it is not "earthquakes" in one place after the other but "social unrest" or political unrest and instability in one place after the other.
This represents the time during the "last generation" of 1914-1994. These things lead up to the "great tribulation" which was the HOLOCAUST.
Further, in the minds of the Jews, a critical event would be the "END of the gentile times" or the "END of the system of things" under the gentile times. That ended in 1947.
A direct fulfillment of the "good news" being preached worldwide and then the "end" will come relates to NH Knorr's worldwide speaking tour early in 1947, "and then the end will come." Thus on November 30, 1947 the Partition Agreement assigned the Jews their own homeland in Palestine that became the State of Israel shortly afterward in the Spring of 1948.
After that, the "sign of the son of man" would begin to appear, which did begin to appear to the elect in January of 1950 and has continued to appear to them, at least as late as December 1998.
JWs, of course, have it all wrong. They think the "end" is Armageddon, but it is not. They think the "great tribulation" is also Armageddon but it is not, it was the Holocaust. Christ doesn't even return until AFTER the tribulation (Holocaust) is over! and after the State of Israel is set up. The State if Israel is represented by the fig tree that begins to blossom shortly after which the messiah appears. The Bible clearly says, "Immediately AFTER the tribulation of those days...the sign of the son of man would appear in heaven." AFTER means AFTER! It doesn't mean continuing which is what the witnesses have to claim when they think Armageddon is the "great tribulation" instead of the Holocaust. Otherwise, Matthew indicates the messiah would arrive shortly after the Holocaust and after the State of Israel would be set up, which signals the "END of the gentile times" (simply called "the end") for the Jews.
Anyway, only part of the barren wasteland of understand now existing with the aposate GB now leading the WTS. The faithful anointed have all the advanced understanding now.