Use the following steps in explanation.
Explanation/Reference:
Explanation:
Step 1: In the name box type B5:I299 (or Click cell B5, shift-click cell I299).

Step 2: On the Home tab, select Conditional Formatting, and click New Rule

Step 3: In The Edit Formatting Rule dialog box select Use a formula to determine which cells to format, type the formula: =WEEKDAY($D5,2)>5, and click the Format button.

Step 4: In the Format Cells dialog box select bold, Underline Single, and click OK.

Step 5: In The Edit Formatting Rule dialog box click Ok.