why doesn't offset work in plotly go.Bar() when axis is datetime?

Question

With go.Bar() one can pass an offset parameter that shifts the position of a bar within the group (barmode is set to 'overlay' for traces with an offset).

This works fine when the x-axis is numeric: but seems to not work when the x-axis is of datetime format:

Is this a bug or a feature? and can offsets work with datetime axes?

import plotly.graph_objects as go
import datetime
from datetime import timedelta
import pandas as pd
from random import random

# generage a datetime index

dates = pd.DatetimeIndex([datetime.date(2022,10,10) + timedelta(x) for x in range(10)]) # datetime index
# dates = range(10) # a list of int; uncomment to see offset 

fig = go.Figure()

for i in range(3):
    s = pd.Series(
        [5*(random()-0.5) for x in range(len(dates))], # random values
        index = dates
    )

    fig.add_trace(
        go.Bar(
            x = s.index,
            y = s,
            offset = 0.15*(i-1),  # has no effect with datetime index
        )
    )

fig.show()

Answer 1

The offset is given in axis units.

When the axis is of type datetime, apparently the unit is a nanosecond (1ns = 1e-9 seconds)

So to notice an offset, you should adjust the magnitude of the offset accordingly.

If you set

offset = 1e7*(i-1), 
width = 2e7 # also in axis units 

you get: