In Daniel 12, a riddle for the length of the end times is given. Read it and you just try squeezing it into 7 years...I can't.
In Matthew 24, Christ gives us a clear sign of when the end times have begun, earthquakes in diverse places. Christ calls this the Beginning of Sorrows. We have had 'earthquakes in diverse places' since the advent of nuclear weapons. This gives us the answer to the riddle of the first seal. The white horse depicts, as one would guess out of context, peace. The bow, an ancient ballistic delivery system, depicts the missile silos, a modern ballistic delivery system (and, nukes are ballistic, once fired, you cannot abort them). Rides out conquering...and with the threat of conquering...