For years, I sat with a stopwatch, estimating scene lengths and then timing the actual lengths of the scenes. For other years, I tracked when we would need to finish each scene in order to finish the day on time. You might say my life was all about time, so much so that I could practically tell what two and a half minutes felt like, even without the stopwatch.
Much of my work is not as time-obsessed these days, though deadlines still loom, and I can still "feel" two and a half minutes. Interestingly, however, the number of days when time turns into not what I planned is still quite high. Time flies when I need it to stand still. Hours go by slowly when I just want to get to the end of a "scene." There are days when I realize I have no more control over real time than, as a PA, I had over the times of the scenes I was estimating. I used to say that a scene's length could change simply because of what the actors had for lunch, and perhaps that is no less true in real life. There will be days when events move slowly--because someone hasn't slept well, or because it is raining, or because of a series of circumstances we can't see. The same events on another day might go completely differently, simply because of factors beyond our control, so that while one day, we are waiting for "it to be over," on another, it feels as though we are struggling to keep up.
Each day, some part of what we do is a result of timing. We can sit with a stopwatch, real or imagined, and keep track of the changes, or we can simply accept the passage of time and the shifts it creates in our lives. As I learned as a PA, holding that stopwatch doesn't make time go the way you want. It simply makes you more aware of the minutes that pass.
The hours go by, whether in the middle of the night or in the sleeping and doing of the day. It's up to us, stopwatch in hand or not, to grab them, not just watch them, to use them, not just count them. If we do, then it won't matter if they change from our estimate. We'll still beat the clock.