What is the date on the package?

I'm not an expert on yeast, by any means. It does have a shelf-life and will become bad with time. Refrigeration should extend the shelf-life of yeast by 4 months. To determine the date of packaging you will have to reach out to the manufacturer. On the package you should find a series of numbers and letters. This should tell the manufacturer when this yeast was packaged. These numbers are worthless to the consumer. All manufactures, by law, must know when their product was made; either by date or by batch number, for recall and safety measures. We all know that most products we purchase sit in warehouses, even during transportation. Sometimes these temp can be quite high. We have no idea what temps our products have been exposed to. Good luck.

How many gallons does one packet make?

It states on the packet, that it will take care of 1 to 6 US gal(s). I normally make 5 to 7 gal(s) when I make my wine. I always use 2 packets of yeast.