I purchased a commercially filled growler today, and it doesn't appear to have the plastic "growler" lid that I usually get when getting one filled at a taproom or beer store. It has a thin metal screw-on cap instead. In my experience the plastic lids will only hold carbonation for maybe up to 3 days, and usually quite a bit less. I don't know whether to expect the same results with a metal lid, though.
Do I need to drink this beer tomorrow, or can I wait for the weekend?