Conditional Formatting In Google Sheets: Can I Use Custom Function In The 'custom Formula Is:' Field?
Answer : Short answer A custom function can't be used as a part of a custom formula in the Google Sheets' conditional formatting built-in user interface. Explanation In Google Sheets, a custom function is like spreadsheet built-in functions but written by the user using the Google Apps Script editor. They can't modify other objects, only return one or multiple values. By the other hand, a custom function only is calculated when it's added to a cell or when at least one of it's parameters changes. They can't use non-deterministic functions as parameters like NOW(), TODAY(), RAND() and RANDBETWEEN(). Test In order to test the statement in the short answer, I created a did the following: Create a simple custom function function two() { return 2; } Add the custom function as part of a custom formula in the conditional formatting side panel =two()=2 Result: Nothing changed. References Custom Functions in Google Sheets I have also found that custom functions c...