You're right, I built this for myself originally not intending for anyone else to see it.

The x-axis is labeled its just hard to see. It's called a "continuous axis" vs a "categorical" one. Categorical shows each data point (in this case a single day). Continuous auto-adjusts to show only the big-picture metric over time.

In other words, what my weight was on December 27th isn't important. What is important is my trend over time. Hope that makes sense.