After 3 years, Kendrick Lamar has released a few more diss tracks targeting Drake and has now saved enough money to pay off the rest of the balance owing on his mortgage to Bank of Montreal. He decides that he would like to be mortgage free. He asks Bank of Montreal for the loan payout amount. The bank cites the payout amount as $6,000,000 + $60,000 interest penalty = $6,060,000. The interest penalty of $60,000 amounts to an additional 3 months of interest for Kendrick at 4% per annum. Kendrick asks Bank of Montreal what the interest penalty is for. He thinks that the bank ought to be grateful for getting their money earlier. What enables Bank of Montreal to charge Kendrick an additional 3 months of interest on top of the loan amount outstanding?