Minus Zero

This morning over breakfast, my sighted spouse commented that her iPhone weather app displayed the temperature as "minus zero".

This immediately set off my Apple bug radar. The minus sign is used to denote a negative number. Because zero is neither negative nor positive, putting a minus sign in front of it seemed like a software bug. (Yes, as a former engineer, I know computers use many formats for storing negative numbers, such as a sign bit or two's complement. But for displaying decimal numbers, it makes no sense to put a minus sign in front of a zero.)

After geeking out, I became curious about VoiceOver. So I checked the Weather app on my iPhone, and VoiceOver read the temperature as zero. I double checked with my sighted spouse and had her look at my phone to verify the minus sign was present. Yes, she assured me, mine had a minus sign too. But VoiceOver wasn't reading it.

I then scrolled over to a couple cities to check their temperatures. It was -5 in Cheyenne, Wyoming, and VoiceOver correctly announced the minus sign.

So now I'm stumped. And if you've read this far and followed everything I said, then riddle me this, Batman:

• Why is there a minus sign in front of a zero?
• More importantly, why does VoiceOver fail to read that minus sign?

Rather than sign my name Paul, I'll sign myself ... Cold in Colorado.