Using built-in spreadsheet functions in a script

Question

I'm using Google App Script for the first time. I'm using it on a Google Doc spreadsheet. I'm trying very simple functions, just to learn the basics. For example this works: ``` function test_hello() { return 'hello'; } ``` But I'm puzzled by this simple one : ``` function test_today() { return today(); } ``` It makes an `#ERROR!` wherever I use it. And when I put my cursor on it, it says : error : ReferenceError: "today" is not defined. While the `today()` function works when used directly in the spreadsheet. Does this mean that in scripts, I cannot use spreadsheet built-in functions? Is there any elegant way around this? Some spreadsheet functions are quite useful to me (I like `weekday()` for example). A non-elegant way could be to create columns to calculate intermediate values that I need, and that can be calculated with spreadsheet functions. But I'd rather avoid something this dirty and cumbersome.

Accepted Answer

Google Apps Script is a subset of JavaScript, spreadsheet functions are currently not supported. For example, if you want to create a function that returns today's date you should write :

```
function test_today(){
return new Date()
}// note that this will  eventually return a value in milliseconds , you'll have to set the cell format to 'date' or 'time' or both ;-)
```

syntax is the same as with sheet functions : `=test_today()` see tutorial

There are many internet ressources on javascript, one of the most useful I found is w3school

Using built-in spreadsheet functions in a script

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