I usually make it as needed, but I have a feeling a day ahead would be fine. Maybe better. If you decide to try, please let us know how it is.

In my experience, the flavors keep a couple of days, but the color goes a little brown.

I make it and keep it in the fridge in a jar fr quite a while. With enough olive oil, it's a good way to keep chopped herbs around.

Make it a day or two ahead but don't add the acid until right before serving and taste for salt

Italian or Mexican? The consensus when I asked this last year was not to freeze Italian salsa verde but I did freeze some Mexican style this winter and it was fine