Welding CO/Argon tank question

Years ago i didnt weld much so a bottle lasted a very long time. It doesent expire. As far as the bottle itself, when you exchange it, the gas supplier re-certifies the bottle.
Nice welder, btw. And you can switch it to gasless/flux core.
Sometimes. I bought a tank from Summit years ago that was so out of date, my local welding shop wouldn't touch it to fill, or give me credit for it. I called Summit and they actually sent a call tag for it and took it back when I read the date code on it. I almost fell out when they refunded me.