Add prototype to descriptions

snippets/addDaysToDate.md

@@ -6,7 +6,7 @@ tags: date,intermediate
 Calculates the date of `n` days from the given date, returning its string representation.
 
 - Use `new Date()` to create a date object from the first parameter.
-- Use `Date.getDate()` and `Date.setDate()` to add `n` days to the given date.
+- Use `Date.prototype.getDate()` and `Date.prototype.setDate()` to add `n` days to the given date.
 - Use `Date.prototype.toISOString()` to return a string in `yyyy-mm-dd` format.
 
 ```js