The Historicist views that in prophetic Scriptures a day is set for a year, in history.
In the symbolic use of language, the Bible says that days denote years.
“Then lie upon your left side, and I will lay the punishment of the house of Israel upon you; for the number of the days that you lie upon it, you shall bear their punishment; For I assign to you a number of days, three hundred and ninety days, equal to the number of the years of their punishment; so long shall you bear the punishment of the house of Israel. And when you have completed these, you shall lie down a second time, but on your right side, and bear the punishment of the house of Judah; forty days I assign you, a day for each year. And you shall set your face toward the siege of Jerusalem, with your arm bared; and you shall prophesy against the city. And, behold, I will put cords upon you, so that you cannot turn from one side to the other, till you have completed the days of your siege.” Ezek 4:4-8
31 At that very hour some Pharisees came, and said to him, “Get away from here, for Herod wants to kill you.” 32 And he said to them, “Go and tell that fox, ‘Behold, I cast out demons and perform cures today and tomorrow, and the third day I finish my course. 33 Nevertheless I must go on my way today and tomorrow and the day following; for it cannot be that a prophet should perish away from Jerusalem.’ 34 O Jerusalem, Jerusalem, killing the prophets and stoning those who are sent to you! How often would I have gathered your children together as a hen gathers her brood under her wings, and you would not! 35 Behold, your house is forsaken. And I tell you, you will not see me until you say, ‘Blessed is he who comes in the name of the Lord!’” Luke 13:31-35
Notice He said, “ I have today, tomorrow, and the next day” (the third day He reached His goal) Messiah’s ministry lasted 3 1/2 years by counting the Passovers in the gospels [John 2:13; 6:4; 18:39]. This is a day for a year.
They refused to go into the land after the spies came back with a terrifying report. For their unbelief, they were kept out of the land for 40 years, a year for every day they had been spying. [Num 14:1-38]
Ezekiel chapter 4 records the symbolic act of the prophet laying on each of his sides as being one day for each year of their punishment. After the reign of Solomon, the kingdom was divided into two separate nations, Israel in the north and Judah in the south. Ezekiel lies on his left side for 390 days for Israel and on his right side for 40 days for Judah. Each day equals one year of judgment.