Thank you...
The bezel (outer dial, on most dive watches have from "0 to 59" on them. This was originally used to tell you how much air you have remaining, in the days B4 dive computers, and of course this is different depending on tank fill, and individual air consumption. That's why some models have red on the dial for the last 10 minutes. However, no matter how you set the dial, whether it is current time, or the amount of estimated minutes, the dial works backwards and you can't set...let's say 40 minutes from now. If you put the current time on the dot or 0, then you would have to look at 40 minutes ahead...in other words it cannot be used as a "count down" timer. If you try the other way, and put the dot 40 minutes from now, then the time would go 58, 59, 60, and then the red on the last 10 minutes would be ineffective. Try it. Even for parking meters, the only way to use it would be, only for 1 exact hour.
I am probably missing the obvious, but if not, then what else was it designed for. No dive master has been able to answer this question. TIA.