wolfgang ziegler

„make stuff and blog about it“

Wrong time in openHAB Docker Container on Synology

January 5, 2020

I recently moved my openHAB installation from a Raspberry Pi to a Docker installation running on my new Synology Diskstation. The whole process worked basically flawless until I noticed that some (time-dependent!) rules would not fire. Or rather - fire an hour late.

The Problem

Looking in the the log files I realized that the timestamps in there were off by an hour.

2020-01-05 19:12:19.439 [INFO ] [pse.smarthome.model.script.pir.rules] - ...
2020-01-05 19:12:29.683 [INFO ] [pse.smarthome.model.script.pir.rules] - ...
2020-01-05 19:16:02.959 [INFO ] [pse.smarthome.model.script.pir.rules] - ...

However, the system time on the Synology Diskstation was correct, so this was obviously an issue with the openHAB Docker container.

The Solution

The solution I came up with wa setting the timezone using the EXTRA_JAVA_OPTS environment variable like this:

  1. Stop the container

  2. Edit the container, find the Environment tab in Advanced Settings and add this entry.


Valid settings for the timezone value can be found here.

Advanced container settings

  1. Start the container again.

  2. Done, time is correct now.