as a grocery store kiosk, you follow your grocery store’s policies, not starbucks. however, you get time and a half pay on federal holidays (christmas day). that’s a law. outside of that, no there is no extra pay for christmas eve, boxing day, etc.

as for taking time off, you must request it in advance like you would any other time off. if anything, further in advance because many people want certain days off.

all starbucks operate differently but at my store we have to work 2/4 days: christmas eve, boxing day, new year’s eve, and/or new year’s day. so we can have two of those days off. but all stores are different in that way.