You have to use it daily, although you can save it for one day in that if you don't use it the day you get it, you can use it the next day, and then spin that day and get another one.
Up
0
Down
You can only hold one free raid pass at a time, but it is possible to do 2 raids in one day if you get a pass for one day but use it the next day, and then you get your raid pass for that day.
e.g. Get a free raid pass on Tuesday, use it on Wednesday, then spin a gym for Wednesday's pass.
Up
0
Down
Another short-sighted move by Niantic. Why should it not be possible to keep unused passes, allowing people who can't be part of raids during the week to use them on the weekends? Perhaps it's another gambit to get people to buy "premium" passes. Feh.
Up
0
Down
Thanks for all the answers.
Niantic Pls...Greed is good but not a lot of greed. just a lil bit