Replace same values in the advanced editor

Advanced editor doesn't offer Find and Replace All capability like notepad, word etc. You can do following (it has manual component though) -

Hold ALT key and select all occurances which you want to replace one by one while holding ALT key (It is not mandatory to hold ALT key when you first select the word, but for all other selections holding ALT key is mandatory).

Once done whatever you do for the first word, the same will be applicable for all other words. 

So, if you have 4 occurances of word datetime, you will need to select all 4 occurances of word datetime one by one while pressing ALT key. If you change datetime to say text, all datetime occurances which you had selected will be converted to text.