CODEWITHSUNDEEP
pythonmatplotlib
Amelio Vazquez-Reina
Amelio Vazquez-Reina

Reputation: 96350

Matplotlib ignoring timezone

The following plot 

import matplotlib
f= plt.figure(figsize=(12,4))
ax = f.add_subplot(111)
df.set_index('timestamp')['values'].plot(ax=ax)
ax.xaxis.set_major_locator(matplotlib.dates.HourLocator(interval=1))
ax.xaxis.set_major_formatter(matplotlib.dates.DateFormatter('%I'))
plt.show()

Renders the hour in the wrong zone (GMT) even though I have:

> df['timestamp'][0]
Timestamp('2014-09-02 18:37:00-0400', tz='US/Eastern')

As a matter of fact, if I comment out the line:

ax.xaxis.set_major_formatter(matplotlib.dates.DateFormatter('%I'))

the hour is rendered in the right time zone.

Why?

Upvotes: 12

Views: 6050

Answers (3)

Andrea
Andrea

Reputation: 259

Using pytz

import pytz
import matplotlib.dates as mdates

my_tz = pytz.timezone('Europe/Berlin')
formatter = mdates.DateFormatter('%m-%d %H:%M', tz=my_tz)

Upvotes: 2

Daniel F
Daniel F

Reputation: 14239

If you don't want to change rcParams (which seems to be an easy fix), then you can pass the timezone to mdates.DateFormatter.

from dateutil import tz
mdates.DateFormatter('%H:%M', tz=tz.gettz('Europe/Berlin'))

The problem is that mdates.DateFormatter completely ignores everything you set in like plot_date or xaxis_date or whatever you use.

Upvotes: 10

Sebastian
Sebastian

Reputation: 5999

I think you can have the desired functionality by setting the timezone in rcParams:

import matplotlib
matplotlib.rcParams['timezone'] = 'US/Eastern'

The formatter is timezone aware and will convert the timestamp to your rcParams timezone (which is probably at UTC), while if you don't format it, it will just take the timestamp and ignore the timezone. If I understand correctly.

More reading:

Upvotes: 20

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