Thoughts on using power reserve mode throughout the day when you know watch is not needed. For example. I'm about to take off for a1.5 hour flight. Power reserve or just airplane? I started my day at 0500 and won't return till 2300. I have 4 flights today. Will going into reserve mode make a difference? Not going to try today because it's my first day wearing the watch and I want to see what the battery life is.