Creating vertical reference line on date axis

Is it possible to create a reference line on a date axis? The below seems to fail for me:

from datetime import datetime
import pandas as pd
import holoviews as hv
import hvplot.pandas
import panel as pn
df = pd.DataFrame(
        "vals": [1, 5, 2, 8, 4],
        "Month": pd.date_range("2020-01-01", periods=5, freq="MS"),
date = datetime(2020, 2, 1)"Month", y="vals") * hv.VLine(date).opts(
    color="red", line_width=2.0
) * hv.HLine(3)

Setting date = 1.5 works.

I haven’t looked at the source code but this working could be because the bar plot does not assume that the x-axis values are in any order and therefore gives an equidistant between the bars regardless of the actual values the bars represent.