GRE Quant Problem: Extreme (Member's Area)

On July 1st, Charlie invested $100$100 in a bank account at 5%5% annual interest, compounding semi-annually. Also on July 1st, Brenda invested the same amount of money in another bank account that earned 5%5% annual interest, compounding quarterly. On what date(s) would the interest earned from two bank accounts be equal?

Solution on the video is given, that, On August 5th and September 5th both Charlie and Brenda didn’t earn anything, interest amount is 0, that’s when their interest is equal, 0 and so August 5th and September 5th are the correct answer.

But my question is, question asks ‘On what date(s) would the interest earned from two bank accounts be equal?’ on those two month no interest been earned from any of the bank, so how can it be the answer?