diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 1bf144d5cc9c96169ee13d99c638936542201e9d..e69b3794f5854cd6c9446b120eb6d64603f8d143 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -10,6 +10,7 @@
         "notskm.clang-tidy",
         "streetsidesoftware.code-spell-checker"
     ],
+    "containerEnv": {"TZ": "${localEnv:TZ:Europe/Berlin}"},
     "runArgs": ["--gpus","all",                     // remove this line in case you have no gpus available
                 "--hostname=${localEnv:HOSTNAME}"], // HOSTNAME needs to be known by the vscode environment. It is probably necessary to add "export HOSTNAME=<hostname>" to the config file of your host machine's bash.
 
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c7fcb81d30f212feb33263ee7af58483ae631fd9..69c4381d0f9230ccf5a416bbf02c4b452b841a8c 100755
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -178,8 +178,7 @@ gcc_9_unit_tests:
     - cd $CI_PROJECT_DIR/build
 
   script:
-    - ctest
-    - ctest --rerun-failed --output-on-failure
+    - ctest --output-on-failure
 
 ###############################################################################
 msvc_17_unit_tests:
diff --git a/Containers/Ubuntu20_04.Dockerfile b/Containers/Ubuntu20_04.Dockerfile
index 97bce073bfd825e0afec97dace698ce28aca6139..c2eea15613787d8f60b835cbb4beec9b0d3893a4 100644
--- a/Containers/Ubuntu20_04.Dockerfile
+++ b/Containers/Ubuntu20_04.Dockerfile
@@ -18,6 +18,10 @@
 
 FROM nvidia/cuda:11.3.1-devel-ubuntu20.04
 
+# timezone
+ARG TZ
+ENV TZ="$TZ"
+
 ARG DEBIAN_FRONTEND=noninteractive
 RUN apt-get update &&   \
     apt-get install -y  \