diff --git a/README.md b/README.md
index 4dbe94d..d0c8d8e 100644
--- a/README.md
+++ b/README.md
@@ -107,6 +107,7 @@ to periodically run a command.
 | -------------------- | -------------------------------------------------------------- |
 | `SCHEDULE`           | A cron expression. Refer to the [cronexpr] doc for the syntax. |
 | `SCHEDULE_CMD`       | A command to run periodically.                                 |
+| `TZ`                 | The timezone to use for the schedule.                          |
 
 ## Key generation
 
diff --git a/client/Dockerfile b/client/Dockerfile
index dc93522..e0e6747 100644
--- a/client/Dockerfile
+++ b/client/Dockerfile
@@ -1,7 +1,7 @@
 FROM alpine:3.20
 
 # Install openssh-client and autossh
-RUN apk add --no-cache openssh-client autossh rsync supercronic nss_wrapper
+RUN apk add --no-cache openssh-client autossh rsync supercronic tzdata nss_wrapper
 
 # Copy entrypoint script
 COPY entrypoint.sh /entrypoint.sh
diff --git a/server/Dockerfile b/server/Dockerfile
index a122437..a50da57 100644
--- a/server/Dockerfile
+++ b/server/Dockerfile
@@ -2,7 +2,7 @@
 FROM alpine:3.20
 
 # Install openssh-server
-RUN apk add --no-cache openssh-server rsync nss_wrapper
+RUN apk add --no-cache openssh-server rsync tzdata nss_wrapper
 
 # Copy entrypoint script
 COPY entrypoint.sh /entrypoint.sh