Theoretically, this prophecy could be taken one step further, since there are accurate records of the dates of the start and end of battle for Constantinople. If "the hour" is taken to be 1/24th of a day, then, by the day-year principle, it would equate to 1/24 of a year i.e. 15 days. Since the battle of Constantinople lasted for several weeks, it is not possible to pin down the exact starting day of this 391-1/24-year prophecy, but if the formula is followed to this degree, it suggests the prophecy's fulfillment should have occurred sometime in May or June 1844.