How do we know when the end of the world is here?

How do we know when the end of the world is here?  (Matthew 24.26-35)

Who is the Son of Man and when will he come?
Jesus Christ--on the Last Day, Judgment Day, Doomsday.
Why is it foolish to go into an inner room or to a secluded place to meet the returning Jesus?
The world and everything in it is going to come to an end.
How will Jesus’ return be similar to lightning?
It will be instantaneous.  He will be seen by everyone, everywhere at the same time.
Jesus gives us a short chronology of the events of the Last Day.  Obviously everything else the Bible tells us must fit into this chronology.  Fill in the timeline.
The Last Day
 

              |                              |                                |                                                     |
              |                              |                                |                                                     |
              |                              |                                |                                                     |
              |                              |                                |                                                     |

             1. _sun and moon go out                   |

                                              |                               |                                                     |
                                             2. _sign of the Son of Man appears
                                                                   
                                                                              |                                                     |
                                                                             3. _all see Jesus     
                                                                                                                                    |
                4. _angels will take the believers to heaven________________________________
 
Fig trees green out just before summer.  When the sun, moon and stars fall, when sign of the Son of Man appears in the sky, when the nations see Jesus coming, when the angels gather the believers into heaven, what day is it?
The Last Day
What are the two meanings of “generation?”
1. _Time--the time it takes for a generation of people to live before they produce the next crop of kids, about 20 years
2. _Race--an entire line of related people
 
Which meaning only can be the correct one?  If so, what does that mean for the Jews?
 Race.  Jesus obviously did not come within the next 20 years.  The Jewish race will be on the face of the earth until the Last Day comes.
Why is it fitting that, of all the human lineages of the world, the Jews will be the one that will survive to the end?
 They are the ones who have received the promises of God through the patriarchs and prophets.  They are the one who were first given the written Word.
How certain is it that this timeline is correct?
 Absolutely certain--as sure as Jesus' words.
In the years following Jesus’ ascension, why would people have to be told what the end of the world would look like?  Could you give examples of times some might be confused?
There would be days so horrible it would seem like this was the end of the world--I think of the fall of Rome to barbarians, the fall of Jerusalem in 70 AD, the bombing of Hiroshima and Nagasaki (which was a Christian city), the firebombing of Dresden, life for a believer in the Soviet gulag, life for protesting Christians (there were a few of them) caught in the Nazi death camps.