I've tried for years, but I can't convince my husband to plan for tomorrow and stop living just for today. Is there anything I can do?
I hate to say it, but I don't think you can convince him. The essence of your question is this: "How do I get him to grow up?" If he's not willing to delay getting or doing things he wants, that's a sign of immaturity. You guys are probably going to struggle with money as long as he has an attitude of "Thank God, it's Friday! Oh, God! It's Monday ..."
Being careful with your money and planning for the future doesn't mean you can't have any fun. It just means you may have to delay certain things for a little while. My wife and I have lots of fun and cool things now. Why? Because we saved like crazy and sacrificed. We lived like no one else, so now we're able to live like no one else. In other words, we paid a price to win.
Your husband's problem is that he's not willing to pay a price for a short period of time. That kind of immature thinking is a one-way ticket to a lifetime of mediocrity. And if you're unwilling to pay the price to win, then you're going to end up paying the price that comes with never having paid the price.