Why isn't February 2007 listed?
Oh. The annotation on the X axis is just a bunch of evenly spaced days. Some damn fool made the individual months have different numbers of days in them, but Excel doesn't know how to make the X axis labels come out on the 1st of the month every month. I tweaked it as best I could, telling Excel to make the ticks 30.47 days apart, but still sometimes they hit on the 31st of a month instead of the 1st of the next month.
This doesn't affect the data. The data points (dots) are always on the 1st and 15th of every month.
