As the title says, why does this 0 rep day show up in the screenshot? If a day has 0 rep, it was probably not very productive. So, why not classify it as idle and not show it like SO does for all idle days?
I have no idea why this shows up, I probably had some rep and then lost it. If that's true I'm not really interested to see that 0 rep day show up in between the days that did matter.