(feature) Add scheduler timezone setup to the native installer

Prompt for the scheduler timezone during interactive installs and support
a --time-zone flag for scripted installs.

Detect a sensible default from POBSYNC_TIME_ZONE, timedatectl, or
/etc/timezone before falling back to UTC, and validate the value with
Python zoneinfo before writing it to pobsync.env.

Document that schedules are evaluated in POBSYNC_TIME_ZONE so production
installs can avoid UTC/local-time ambiguity.

README.md

@@ -55,6 +55,7 @@ Common overrides:
 ```
 sudo scripts/install-systemd \
   --backup-root /mnt/backups/pobsync \
+  --time-zone Europe/Amsterdam \
   --allowed-hosts backup.example.com,localhost,127.0.0.1 \
   --csrf-trusted-origins https://backup.example.com
 ```
@@ -64,6 +65,9 @@ installer to rewrite an existing `/etc/pobsync/pobsync.env`.
 Use `--non-interactive` for scripted installs. Use `--verbose` when you want to see the underlying apt, pip, Django, and
 systemd output.
 
+Schedules are evaluated in `POBSYNC_TIME_ZONE`. The installer defaults this to the server timezone when it can detect
+one, otherwise `UTC`; override it with `--time-zone Europe/Amsterdam` or by editing `/etc/pobsync/pobsync.env`.
+
 For MariaDB support, add:
 
 ```

scripts/install-systemd

@@ -17,6 +17,7 @@ if [ -n "${POBSYNC_BACKUP_ROOT:-}" ]; then
     BACKUP_ROOT_EXPLICIT=1
 fi
 WEB_BIND=${POBSYNC_WEB_BIND:-127.0.0.1:8010}
+TIME_ZONE=${POBSYNC_TIME_ZONE:-}
 FORCE_ENV=0
 INSTALL_OS_PACKAGES=1
 WITH_NGINX=0
@@ -74,6 +75,10 @@ while [ "$#" -gt 0 ]; do
             WEB_BIND=$2
             shift 2
             ;;
+        --time-zone)
+            TIME_ZONE=$2
+            shift 2
+            ;;
         --force-env)
             FORCE_ENV=1
             shift
@@ -148,6 +153,38 @@ if [ -f "$ENV_FILE" ] && [ "$FORCE_ENV" -ne 1 ] && [ "$BACKUP_ROOT_EXPLICIT" -ne
     fi
 fi
 
+detect_time_zone() {
+    if [ -n "$TIME_ZONE" ]; then
+        printf '%s\n' "$TIME_ZONE"
+        return
+    fi
+
+    if [ -n "${POBSYNC_TIME_ZONE:-}" ]; then
+        printf '%s\n' "$POBSYNC_TIME_ZONE"
+        return
+    fi
+
+    if command -v timedatectl >/dev/null 2>&1; then
+        detected=$(timedatectl show -p Timezone --value 2>/dev/null || true)
+        if [ -n "$detected" ]; then
+            printf '%s\n' "$detected"
+            return
+        fi
+    fi
+
+    if [ -f /etc/timezone ]; then
+        detected=$(sed -n '1p' /etc/timezone | tr -d '[:space:]')
+        if [ -n "$detected" ]; then
+            printf '%s\n' "$detected"
+            return
+        fi
+    fi
+
+    printf 'UTC\n'
+}
+
+TIME_ZONE=$(detect_time_zone)
+
 run_step() {
     label=$1
     shift
@@ -261,6 +298,7 @@ if [ "$INTERACTIVE" -eq 1 ]; then
     SERVICE_GROUP=$(prompt_value "Service group" "$SERVICE_GROUP")
     BACKUP_ROOT=$(prompt_value "Backup storage path" "$BACKUP_ROOT")
     WEB_BIND=$(prompt_value "Gunicorn bind address" "$WEB_BIND")
+    TIME_ZONE=$(prompt_value "Scheduler time zone" "$TIME_ZONE")
     ALLOWED_HOSTS=$(prompt_value "Allowed hosts" "$ALLOWED_HOSTS")
     CSRF_TRUSTED_ORIGINS=$(prompt_value "CSRF trusted origins, comma-separated or blank" "$CSRF_TRUSTED_ORIGINS")
     INSTALL_OS_PACKAGES=$(prompt_yes_no "Install required OS packages with apt-get" "$INSTALL_OS_PACKAGES")
@@ -331,6 +369,12 @@ if ! command -v python3 >/dev/null 2>&1; then
     exit 1
 fi
 
+if ! env POBSYNC_INSTALL_TIME_ZONE="$TIME_ZONE" python3 -c "import os; from zoneinfo import ZoneInfo; ZoneInfo(os.environ['POBSYNC_INSTALL_TIME_ZONE'])" >/dev/null 2>&1; then
+    echo "Invalid time zone: $TIME_ZONE" >&2
+    echo "Use an IANA timezone such as UTC or Europe/Amsterdam." >&2
+    exit 1
+fi
+
 if ! command -v rsync >/dev/null 2>&1; then
     echo "rsync is required." >&2
     exit 1
@@ -416,6 +460,7 @@ POBSYNC_DJANGO_CSRF_TRUSTED_ORIGINS=$CSRF_TRUSTED_ORIGINS
 
 POBSYNC_HOME=/var/lib/pobsync
 POBSYNC_BACKUP_ROOT=$BACKUP_ROOT
+POBSYNC_TIME_ZONE=$TIME_ZONE
 POBSYNC_SQLITE_PATH=/var/lib/pobsync/pobsync.sqlite3
 POBSYNC_STATIC_ROOT=/var/lib/pobsync/static
 

src/pobsync_backend/stats_summary.py

@@ -54,23 +54,23 @@ def collect_dashboard_stats(*, hosts: Iterable[HostConfig], global_config: Globa
 def collect_host_stats(*, host: HostConfig, limit: int = 8) -> dict[str, Any]:
     runs = list(host.runs.select_related("snapshot").filter(status=BackupRun.Status.SUCCESS).order_by("-started_at", "-created_at")[:50])
     real_runs = [_run_summary(run) for run in runs if _is_real_run(run)]
-    real_runs = [run for run in real_runs if run["has_stats"]][:limit]
+    trend_runs = [run for run in real_runs if run["has_stats"]][:limit]
     latest_snapshot = host.snapshots.order_by("-started_at", "-discovered_at", "-id").first()
     latest_snapshot_stats = _snapshot_summary(latest_snapshot) if latest_snapshot else {}
 
-    literal_values = [_int_at(run, "rsync", "literal_data_bytes") for run in real_runs]
+    literal_values = [_int_at(run, "rsync", "literal_data_bytes") for run in trend_runs]
     literal_values = [value for value in literal_values if value is not None]
-    matched_values = [_int_at(run, "rsync", "matched_data_bytes") for run in real_runs]
+    matched_values = [_int_at(run, "rsync", "matched_data_bytes") for run in trend_runs]
     matched_values = [value for value in matched_values if value is not None]
     max_literal = max(literal_values) if literal_values else 0
     max_matched = max(matched_values) if matched_values else 0
 
     return {
-        "runs": [_with_bar_percentages(run, max_literal=max_literal, max_matched=max_matched) for run in real_runs],
+        "runs": [_with_bar_percentages(run, max_literal=max_literal, max_matched=max_matched) for run in trend_runs],
         "latest_run": real_runs[0] if real_runs else {},
         "latest_snapshot": latest_snapshot_stats,
         "avg_literal_data_bytes": _average(literal_values),
-        "avg_daily_literal_data_bytes": _average_daily_literal(real_runs),
+        "avg_daily_literal_data_bytes": _average_daily_literal(trend_runs),
         "total_literal_data_bytes": sum(literal_values),
         "total_matched_data_bytes": sum(matched_values),
     }

src/pobsync_backend/templates/pobsync_backend/dashboard.html

@@ -90,7 +90,14 @@
                 <span class="muted">none</span>
               {% endif %}
             </td>
-            <td>{% if host.next_run_at %}{{ host.next_run_at }}{% else %}<span class="muted">none</span>{% endif %}</td>
+            <td>
+              {% if host.next_run_at %}
+                {{ host.next_run_at|date:"Y-m-d H:i T" }}
+                <div class="muted">{{ scheduler_timezone }}</div>
+              {% else %}
+                <span class="muted">none</span>
+              {% endif %}
+            </td>
             <td>{{ host.stats_summary.latest_run.rsync.literal_data_bytes|filesizeformat }}</td>
             <td>{{ host.run_count }}</td>
             <td>d{{ host.retention_daily }} w{{ host.retention_weekly }} m{{ host.retention_monthly }} y{{ host.retention_yearly }}</td>

src/pobsync_backend/templates/pobsync_backend/host_detail.html

@@ -52,7 +52,7 @@
           <div><strong>Schedule expression:</strong> {{ schedule.cron_expr }}</div>
           <div class="muted">Evaluated by the pobsync scheduler service.</div>
           <div><strong>Enabled:</strong> {{ schedule.enabled|yesno:"yes,no" }}</div>
-          <div><strong>Next run:</strong> {{ next_run_at|default:"" }}</div>
+          <div><strong>Next run:</strong> {% if next_run_at %}{{ next_run_at|date:"Y-m-d H:i T" }} <span class="muted">{{ scheduler_timezone }}</span>{% endif %}</div>
           <div><strong>Prune:</strong> {{ schedule.prune|yesno:"yes,no" }}</div>
           <div><strong>Last status:</strong> {{ schedule.last_status|default:"" }}</div>
           <div><strong>Last started:</strong> {{ schedule.last_started_at|default:"" }}</div>

src/pobsync_backend/tests/test_views.py

@@ -50,6 +50,8 @@ class ViewTests(TestCase):
         self.assertContains(response, "web-01")
         self.assertContains(response, "20260519-021500Z__ABCDEFGH")
         self.assertContains(response, "success")
+        self.assertContains(response, f"Run {run.id}")
+        self.assertContains(response, "manual")
 
     def test_dashboard_renders_backup_trend_summary(self) -> None:
         self.client.force_login(self.staff_user)
@@ -91,6 +93,7 @@ class ViewTests(TestCase):
         self.assertContains(response, "Avg Daily New")
         self.assertContains(response, "Days Until Full")
         self.assertContains(response, "Next Run")
+        self.assertContains(response, "UTC")
         self.assertContains(response, "10")
         self.assertContains(response, f"Run {run.id}")
         self.assertContains(response, "manual")
@@ -554,6 +557,7 @@ class ViewTests(TestCase):
         self.assertContains(response, "Schedule expression")
         self.assertContains(response, "Evaluated by the pobsync scheduler service.")
         self.assertContains(response, "Next run:")
+        self.assertContains(response, "UTC")
         self.assertContains(response, "20260519-021500Z__ABCDEFGH")
         self.assertContains(response, "Discover snapshots")
         self.assertContains(response, "Edit schedule")

src/pobsync_backend/views.py

@@ -58,6 +58,7 @@ def dashboard(request):
         "hosts": hosts,
         "global_config": global_config,
         "stats_summary": stats_summary,
+        "scheduler_timezone": timezone.get_current_timezone_name(),
         "latest_runs": BackupRun.objects.select_related("host", "snapshot").order_by("-created_at")[:10],
         "counts": {
             "global_configs": GlobalConfig.objects.count(),
@@ -271,6 +272,7 @@ def host_detail(request, host: str):
         "host": host_config,
         "schedule": schedule,
         "next_run_at": _next_run_for_schedule(schedule, host_config),
+        "scheduler_timezone": timezone.get_current_timezone_name(),
         "discovery": inspect_snapshot_discovery(host=host_config),
         "host_checks": host_checks,
         "host_check_summary": summarize_self_checks(host_checks),