when plotting with vbar on an xaxis that's a datetime axis, how can I set the width of the bars to be "one day"?

Question

This certainly makes the width of the bars wider, but would be better to set them to "1 day" wide:

source = ColumnDataSource(df)
p = figure(x_axis_type="datetime", height=200, ...)
...
c.vbar('dt', top='pct_change', width=100000000, source=source)

Answer 1

You can give a timedelta object as the width keyword argument, it will be converted to milliseconds.

import datetime

...

c.vbar('dt', top='pct_change', width=datetime.timedelta(days=1), source=source)

NumberSpec can accept datetime values, unless accept_datetime is set to false.