There's JM currently and there will be after the contract. Here they call it 'cash flying'. I've been called for it before and usually just say no, because I commute.
If you're finishing a trip and you get volunteered for additional flying, there's provisions in the contract to provide 150% pay and you get your days off back. Currently, no structure is in place to get you anything. I've been over on a day off before and lost the day off. I really hope this contract passes, it's a MASSIVE improvement over what we currently have.