Select the range, click Ctrl+1 to format the cells, and on the Number tab, choose Custom, and in the Type box, enter d (for day), type Ctrl+J to enter a line feed right in the format, then enter mmm (for three-letter month abbreviation), and press Enter.

To build a Gantt chart to show a time schedule, you can use Conditional Formatting with a formula based on AND and OR functions. In the example shown, the formula applied to D5 is: =IF($B5<$C5,AND(D$4>=$B5,D$4<=$C5),OR(D$4>=$B5,D$4<$C5)) Note references are mixed to lock rows and columns as needed in order to test each cell in the grid correctly.

The MONTH function is used to compare months in the header row. When they are different, the month name is displayed. To build a Gantt chart by week, you can use conditional formatting applied with a formula based on the AND function. In the example shown, the formula applied to D5 is: =AND ((D$5+6)>=$B6,D$5