You could look at money as condensed time - you've worked for the money and saved it up. At some point if you save enough you can stop working and live off that savings. And then you have time.
Fallacy. With money you can avoid working. You cant buy time. Those are two very different things. You know who benefits from you being confused on that point? Your employer. "work hard and then you'll be able to buy time. Not now of course, now you're working hard. But later you'll buy time trust me bro"
What is "enough" and how much guarantee is there that I'll reach that?
It's rather similar to what investing calls the DCF - but with time: time I have today is worth more than time I might have in future. For several reasons:
Time I have today is guaranteed. The future is unknown. But rather known, is that in the future I'll be older, my health and energy lower and therefore my options limited. The quality of "time" is potentially much higher when you are 20 than when you are 83. And then there's the risk that I don't even make it far beyond my 70ies.