chart x column "{col}" is typed "{type}", so...

Warnings reference › chart:x:banded:*

Identifier

chart:x:banded:*

Raised by

Charts

Since

1.63.0

What happened

The x column is typed text (or is untyped, which an inference over an empty row set produces), and every one of its values reads as a date or a number. The chart drew them as categories - evenly spaced bands in row order - which looks like a time series with the gaps removed. Only text/untyped columns are reported: a lookup whose codes are integers, or a boolean drawn as two bands, is the caller stating what the column holds, and telling them it looks continuous would be noise.

The fix

Type the column so the inference is not needed, or pin the axis with axis.x.scale.

The smallest fix

columns: [{ id: 'day', type: 'date' }]

Reference

Covered in full at the API reference.