That's just a start!
There is NO word LITERAL in this instruction. Now the subject is what? And to WHOM is this instruction given, and WHY was it necessary for these peoples to be given this particular instruction?
These peoples were in Egypt, in bondage, and they were brought out of Egypt after a series of plagues upon Egypt because of WHY? The Heavenly Father had sent them there in the first place and it was HE that guided them to that promised land.... Hint Hint Hint... Paul says that these things were written for our warning as to what would be again to end this second (according to Peter) flesh age.
Now in 'spirit' or on God's measurement of time Peter says that one day with the Lord is as a thousand years... Remember in Genesis 6 God shorten the life span of flesh and Methuselah is recorded to have lived nearly a thousand years.... or one day with the Lord.
All scripture fits together and Peter explains for us Christians very simply so as to end confusion.