["bug"] Chart rules don't match position of plotted points

[PhilMiller]

Description:

There's a line marking what should be May 3 on the axis. No point lies on that line. The point closest to it shows May 2

Steps to reproduce:

Expected behavior:

Every 7th point should lie exactly on one of the chart rule lines, and that point should correspond to the date labeled at the tick below the rule line.

What I got instead:

(screenshots if applicable)