Help with Conditional Formatting?

I have a table that contains data about the weather, obtained from a device which records that data every hour on the hour. 

I need a conditional formatting formula which adds a bottom border to every 24th row to separate the days, making the table easier to read.

THE PROBLEM is that =mod(row(),24)=0 will include the first three rows of the worksheet which is my header.

The question then is how do I get the formula to skip the first three rows of the table, and THEN start formatting every 24th row?