What happens if I have an Xbox Game Pass subscription and then redeem an Xbox Live Gold card (1 month), will the month be added?

I still have a Game Pass subscription for one month, but I have a Live Gold card for one month. Now the question is if I redeem it now, the month is simply added to it or the month then runs simultaneously with the Game Pass subscription. And can I keep the card for another month without the code expiring?

At the same time, since one is for free games access to selected games and xbox live is intended for online activities with other players