When I woke up on New Year’s Day and pulled my iPhone, running Sleep Cycle, out from under the covers, I noticed the crescent moon in my status bar that indicates “Do Not Disturb” mode was still on. This struck me as slightly odd, as it was scheduled to turn off at seven in the morning, a full three and a half hours before I actually woke up. [1] In the time, I missed a bunch of New Years text messages, but no phone calls. Thinking nothing of it, I switched Do Not Disturb back off, got up, and started doing a little relaxed, early morning reading on my iPad.

A few articles in on Flipboard, I noticed the crescent on the iPad’s status bar too. I turned it off, and resumed my reading. Then, I came across an article on the problem. That, I guess, explained that. If it’s a bug, then it’s a damned useful one. Like anyone who had been out ringing in the new year, the last thing I wanted was my phone buzzing for some reason or another and waking me before I was ready. It’s exactly the sort of “I didn’t know I wanted it until I had it” feature that makes Apple products so useful.

That Apple put out a new ad touting the Do Not Disturb feature today makes me believe even more that this was intentional. Though, I could be wrong. Working for a startup company, even in a non-technical role, has taught me a few things about software development—the sort of axiomatic things that you hear but never experience until you’re in that world. I’m talking about stuff like the Ninety-ninety rule. The larger, more complicated, and more interrelated any system is, the more likely a small change in a component part can cause trouble elsewhere, and if that trouble is, itself, small, it can easily escape notice.

You know the show-stopping bugs when they happen. Your screen turns blue or black. A box comes up with an indecipherable error message. All the data in a folder suddenly vanishes without a trace. These are the ones that you drop everything to fix, without even creating an issue in your bug tracker. The little ones… they’re harder to spot. Even a company like Apple can have trouble with those. Whether it was an overlooked bug, or a secret easter egg feature, I certainly didn’t mind not having my sleep interrupted. A new year begins best after a good night’s sleep. And bug-crushing is easier when you’re well rested.