How to plot stacked event duration (Gantt Charts)

• I think you are trying to create a Gantt plot.
• How to create a Gantt plot suggests using hlines
• Tested in matplotlib 3.4.2

import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as dt

# using df from the OP

# convert columns to a datetime dtype
df.amin = pd.to_datetime(df.amin)
df.amax = pd.to_datetime(df.amax)

fig, ax = plt.subplots(figsize=(8, 5))
ax = ax.xaxis_date()
ax = plt.hlines(df.index, dt.date2num(df.amin), dt.date2num(df.amax))

• The following code also works

# using df from the OP

df.amin = pd.to_datetime(df.amin)
df.amax = pd.to_datetime(df.amax)

fig, ax = plt.subplots(figsize=(8, 5))
ax = plt.hlines(df.index, df.amin, df.amax)