In Bible prophecy, 1 prophetic day = 1 literal year
To understand events foretold in Bible prophecy, we use the day for a year principle. This principle applies in the context of prophetic symbols when God is revealing the future through prophetic symbols. We see this in the books of Daniel and Revelation.
Where in the Bible do we learn about the day for a year principle? God explained to the Israelites that a day symbolizes or equates to a year when they were told they would wander in the wilderness for 40 years, one year for each of the 40 days the spies spent scouting the Promised Land.
“According to the number of the days in which you spied out the land, forty days, for each day you shall bear your guilt one year, namely forty years…” (Numbers 14:34 NJKV).
God explained the day for year principle again when he commanded the prophet Ezekiel to lie on his side to symbolically bear the sin of the house of Judah.
“And when you have completed them, lie again on your right side; then you shall bear the iniquity of the house of Judah forty days. I have laid on you a day for each year” (Ezekiel 4:6 NKJV).
Context can help us discern when the day to a year principle applies. This principle doesn’t apply every time the Bible discusses time or a number. Literal numbers describe actual events that happened, often historical events. For example, Noah stayed in the ark for 40 days, not 40 years.
Prophetic numbers use symbolic time codes given along with other prophetic symbols to reveal events to occur in the future.