Add ability to set timezone for Docker container (#5383)

Signed-off-by: Amir Zarrinkafsh <nightah@me.com>

3 files changed, 3 insertions, 1 deletions

diff --git a/changelog.d/5383.feature b/changelog.d/5383.feature
new file mode 100644

index 0000000000..5d084cf0b2
--- /dev/null
+++ b/changelog.d/5383.feature
@@ -0,0 +1 @@
+Add ability to change Docker containers [timezone](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) with the `TZ` variable.
diff --git a/docker/Dockerfile b/docker/Dockerfile

index 0939cadf39..79276209f6 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -66,6 +66,7 @@ RUN apk add --no-cache --virtual .runtime_deps \
         libpq \
         zlib \
         su-exec \
+        tzdata \
         xmlsec
 
 COPY --from=builder /install /usr/local
diff --git a/docker/README.md b/docker/README.md

index b62417c281..46bb9d2d99 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -63,7 +63,6 @@ The following environment variables are supported in `generate` mode:
 * `UID`, `GID`: the user id and group id to use for creating the data
   directories. Defaults to `991`, `991`.
 
-
 ## Running synapse
 
 Once you have a valid configuration file, you can start synapse as follows:
@@ -91,6 +90,7 @@ The following environment variables are supported in run mode:
 * `SYNAPSE_CONFIG_PATH`: path to the config file. Defaults to
   `<SYNAPSE_CONFIG_DIR>/homeserver.yaml`.
 * `UID`, `GID`: the user and group id to run Synapse as. Defaults to `991`, `991`.
+* `TZ`: the [timezone](https://en.wikipedia.org/wiki/List_of_tz_database_time_zones) the container will run with. Defaults to `UTC`.
 
 ## TLS support