What is “the year-day system” of interpreting Bible prophecy?

One question visitors to Historicism.com (the parent site of ProphecyBlog.net) have asked me over and over again throughout the years is something like, “Why do you say all time periods in Bible prophecy should be interpreted taking a year of history for every day in the prophecy?” In other words, why should all Bible prophecy chronological predictions be interpreted using the scale 1 day : 1 year?

I was sure I’d written something on this subject before… but I’m almost 40 now so my memory is not what it used to be! (or so I’m told.) But having searched my own site (Historicism.com) I can’t find something good enough to recommend to people asking this question. So here is my solution: an excerpt from The Approaching End of the Age, by Henry Grattan Guinness, in which he explains “the year-day system” of interpreting Bible prophecy.