Datetime x axis in bokeh.charts.Area
<p>Why I plot my data with a <code>datetime</code> series as x axis, it is interpreted as a <code>datetime</code> value, but the wrong one: my 2016 times are interpreted as  milliseconds after 1970-1-1. Code:</p>

<pre><code>from __future__ import absolute_import, division, print_function
from __future__ import unicode_literals

from datetime import datetime
import pandas as pd
from bokeh.charts import Area, show, output_file

df = pd.DataFrame()
df['date'] = [datetime(2016, 1, 1), datetime(2016, 1, 2), datetime(2016, 1, 3)]
df['v1'] = [1, 2, 3]
df['v2'] = [4, 4, 3]

p = Area(df, x='date', y=['v1', 'v2'], title="Area Chart",
         legend="top_left", xscale='datetime', stack=True,
         xlabel='time', ylabel='values')

output_file("area.html", title="Area Chart")
show(p)
</code></pre>

<p><a href="https://i.stack.imgur.com/YuPm1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YuPm1.png" alt="Area chart screenshot"></a></p>

<p>Is there a way I can get <code>bokeh.charts.Area</code> recognize my <code>datetime</code> data, or do I have to construct the plot myself using <code>figure()</code>?</p>

<p>Additional data: bokeh 0.11.1 on Python 2.7</p>