While Excel is smart enough to know you mean a fraction when you enter 2 2/3 , if you just enter just 2/3 , it defaults to the date format. To get around the problem, just enter a 0 in front of the ...

Left to its own devices, Excel will convert your fractions into dates as soon as you enter them in your spreadsheet. See how you can work around this problem.

How to create conditional formatting rules in Excel Once the custom value formats exist, you can apply them using conditional formatting rules. Right now, the format is set to General.