When I set an alarm, my clock, now running on the computer in my pocket, is smart enough to tell me how much time will pass until the alarm is scheduled to sound. This has eliminated the old problem of sleeping past meetings before being surprised by an alarm precisely half a day after I had originally planned to wake.
The price has been having to know exactly how little I will sleep: a usually depressing fact that had previously been obscured by my difficulty doing time arithmetic in my most somnolent moments.
When I am traveling, I use the alarm on the computer not in my pocket, which grants me the same depressing realization–and makes me even less able to sleep.
The trick I use to avoid this common problem is a nifty new invention called the “24 hour” clock. Unfortunately, my bedside alarm (which I believe my parents received as a wedding gift) doesn’t support such new-fangled technology, but at least my phone does.