Shift differential

Hey guysI'm starting a new job and I understand that they pay $2.75 extra for working evening shift, my question is, when I work weekends do I get the shift differential plus weekend premium or just the weekend premium?
You need to read your union contract.Mine double premiums for weekend evenings and nights. I also get a premium for working Saturday and Sunday dayshifts.Every contract is different, so you really need to read yours and understand it.

Thanks Fiona