I assume the "trim(right .... I get something completely different" means you are seeing the timezone. Your result probably doesn't show it because the text area you set up is too small but if you extended that out you would see something like:
Tue Oct 13 2020 09:24:49 GMT-0
If you shrink the size of your left command to just the first 24 characters, you don't get the timezone.
TEXT | set text = right(trim(left(Browser.ExecJS("Date()"),24)),8)
This does exactly what you have already figured out, except only getting the first 24 characters, but then gets just the 8 characters on the right side.