calendar

server/README.md

@@ -3,9 +3,9 @@
 Two Flask services with separate responsibilities and separate databases:
 
 - **main app** (`app.py`) — all user-facing views: login, home, notes,
-  notifications, clipboard, API docs and the `/sensors` dashboard. It owns the
+  notifications, clipboard, calendar, API docs and the `/sensors` dashboard. It
-  **main app** database (`main_app.db`: users, notes, notifications and clipboard
+  owns the **main app** database (`main_app.db`: users, notes, notifications and
-  file metadata) and proxies data requests to the sensors API.
+  clipboard file metadata) and proxies data requests to the sensors API.
 - **sensors app** (`sensors_app.py`) — API only. It owns the **sensors**
   database (`sensors.db`, tables `sensor` and `sensor_readout`) and has no
   knowledge of users. Its API is open to every user on the local machine.
@@ -56,6 +56,7 @@ server/
     ├── notes.html
     ├── notifications.html
     ├── clipboard.html
+    ├── calendar.html
     ├── docs.html
     └── sensors.html
 ```
@@ -187,6 +188,19 @@ automatically):
 alembic -c alembic_users.ini upgrade head
 ```
 
+## Calendar
+
+The main app provides a `/calendar` page with two views for browsing sensor
+readouts:
+
+- **month** (`/calendar?view=month&year=YYYY&month=MM`) — calendar grid of the
+  given month, each day lists readouts (sensor, time, type, value)
+- **week** (`/calendar?view=week&date=YYYY-MM-DD`) — list of the seven days of
+  the week containing the given date
+
+Readouts are fetched from the sensors API through the
+`GET /api/sensors/:id/readouts/range?from=...&to=...` endpoint.
+
 ## Notes
 
 Logged-in users manage their own private short notes at `/notes`. Each note has
@@ -349,7 +363,7 @@ deployment path or user is different.
 
 | Service | Port | Routes |
 |---|---|---|
-| main | 8000 | `/`, `/login`, `/home`, `/clipboard`, `/notes`, `/notifications`, `/sensors`, `/api/docs`, `/api/*` (proxy) |
+| main | 8000 | `/`, `/login`, `/home`, `/clipboard`, `/calendar`, `/notes`, `/notifications`, `/sensors`, `/api/docs`, `/api/*` (proxy) |
 | sensors | 8001 | `/api/*` (sensors and readouts) |
 
 ### Tests

server/app.py

@@ -2,7 +2,9 @@ import fcntl
 import os
 import uuid
 from contextlib import contextmanager
+from datetime import date, datetime, timedelta, timezone
 from pathlib import Path
+from zoneinfo import ZoneInfo
 
 import click
 from flask import (
@@ -49,6 +51,34 @@ def format_bytes(value: int) -> str:
     return f"{int(size)} B"
 
 
+LOCAL_TZ_DEFAULT = "Europe/Warsaw"
+
+
+def _calendar_tz(name):
+    try:
+        return ZoneInfo(name)
+    except Exception:
+        return ZoneInfo(LOCAL_TZ_DEFAULT)
+
+
+def _parse_date_arg(raw):
+    value = (raw or "").strip()
+    if not value:
+        return None
+    try:
+        return date.fromisoformat(value)
+    except ValueError:
+        return None
+
+
+def _day_bounds_utc(day: date, tz):
+    start_local = datetime(day.year, day.month, day.day)
+    end_local = start_local + timedelta(days=1)
+    start_utc = start_local.replace(tzinfo=tz).astimezone(timezone.utc).replace(tzinfo=None)
+    end_utc = end_local.replace(tzinfo=tz).astimezone(timezone.utc).replace(tzinfo=None)
+    return start_utc, end_utc
+
+
 def create_app():
     app = Flask(__name__)
 
@@ -326,6 +356,155 @@ def create_app():
         flash(f"Deleted {name}.", "success")
         return redirect(url_for("clipboard_page"))
 
+    @app.route("/api/sensors/<int:sensor_id>/readouts/range")
+    @login_required
+    def api_sensor_readouts_range(sensor_id):
+        return _proxy(
+            lambda: sensors.sensor_readouts_range(sensor_id, request.args.to_dict())
+        )
+
+    @app.route("/calendar")
+    @login_required
+    def calendar_page():
+        view = (request.args.get("view") or "month").strip().lower()
+        if view not in ("month", "week"):
+            view = "month"
+        tz = _calendar_tz(request.args.get("tz") or LOCAL_TZ_DEFAULT)
+        now_local = datetime.now(tz)
+
+        year = now_local.year
+        month = now_local.month
+        week_start = None
+        week_end = None
+        week_prev = None
+        week_next = None
+        days = []
+        month_weeks = None
+
+        if view == "week":
+            week_date = _parse_date_arg(request.args.get("date")) or now_local.date()
+            week_start = week_date - timedelta(days=week_date.weekday())
+            week_end = week_start + timedelta(days=6)
+            week_prev = week_start - timedelta(days=7)
+            week_next = week_start + timedelta(days=7)
+            day_list = [week_start + timedelta(days=i) for i in range(7)]
+            range_from = _day_bounds_utc(week_start, tz)[0]
+            range_to = _day_bounds_utc(week_end + timedelta(days=1), tz)[0]
+        else:
+            year = int(request.args.get("year") or now_local.year)
+            month = int(request.args.get("month") or now_local.month)
+            if not 1 <= month <= 12:
+                month = 1
+            first_day = date(year, month, 1)
+            next_year = year + 1 if month == 12 else year
+            next_month = 1 if month == 12 else month + 1
+            last_day = date(next_year, next_month, 1) - timedelta(days=1)
+            day_list = []
+            current = first_day
+            while current <= last_day:
+                day_list.append(current)
+                current += timedelta(days=1)
+            range_from, _ = _day_bounds_utc(first_day, tz)
+            range_to, _ = _day_bounds_utc(last_day, tz)
+            week_start = first_day - timedelta(days=first_day.weekday())
+            week_end = last_day
+
+        readouts_by_day = {day: [] for day in day_list}
+        sensor_names = {}
+        try:
+            listed = sensors.list_sensors()
+            for sensor in listed[1] or []:
+                sensor_id = int(sensor["id"])
+                sensor_names[sensor_id] = sensor["name"]
+                status, payload = sensors.sensor_readouts_range(
+                    sensor_id,
+                    {"from": range_from.isoformat(), "to": range_to.isoformat()},
+                )
+                if status != 200:
+                    continue
+                for item in payload or []:
+                    raw_ts = (item.get("timestamp") or "").rstrip("Z")
+                    ts = datetime.fromisoformat(raw_ts) if raw_ts else None
+                    if ts is None:
+                        continue
+                    local_day = ts.replace(tzinfo=timezone.utc).astimezone(tz).date()
+                    if local_day in readouts_by_day:
+                        readouts_by_day[local_day].append(
+                            {
+                                "id": item.get("id"),
+                                "sensor_id": item.get("sensor_id") or sensor_id,
+                                "type": item.get("type"),
+                                "value": item.get("value"),
+                                "timestamp": ts,
+                            }
+                        )
+        except SensorsAPIError:
+            pass
+
+        days = [
+            {"date": day, "readouts": readouts_by_day.get(day, [])}
+            for day in day_list
+        ]
+
+        month_weeks = None
+        if view == "month":
+            first_monday = week_start
+            last_sunday = week_end + timedelta(days=6 - week_end.weekday())
+            end_exclusive = last_sunday + timedelta(days=1)
+            weeks = []
+            week = []
+            current = first_monday
+            while current < end_exclusive:
+                week.append(
+                    {
+                        "date": current,
+                        "in_month": current.month == month,
+                        "readouts": readouts_by_day.get(current, []),
+                    }
+                )
+                if current.weekday() == 6:
+                    weeks.append(week)
+                    week = []
+                current += timedelta(days=1)
+            if week:
+                weeks.append(week)
+            month_weeks = weeks
+
+        if month == 1:
+            prev_year, prev_month = year - 1, 12
+        else:
+            prev_year, prev_month = year, month - 1
+        if month == 12:
+            next_year, next_month = year + 1, 1
+        else:
+            next_year, next_month = year, month + 1
+
+        month_names = (
+            "January", "February", "March", "April", "May", "June",
+            "July", "August", "September", "October", "November", "December",
+        )
+        month_label = f"{month_names[month - 1]} {year}"
+
+        return render_template(
+            "calendar.html",
+            user=current_user,
+            view=view,
+            year=year,
+            month=month,
+            week_start=week_start,
+            week_end=week_end,
+            days=days,
+            month_weeks=month_weeks,
+            sensor_names=sensor_names,
+            prev_year=prev_year,
+            prev_month=prev_month,
+            next_year=next_year,
+            next_month=next_month,
+            week_prev=week_prev,
+            week_next=week_next,
+            today=now_local.date(),
+        )
+
     # --- Notifications (stored in main_app.db) ---
 
     @app.route("/notifications")

server/sensors_app.py

@@ -7,6 +7,20 @@ from config import sensors_database_uri
 from models import Sensor, SensorReadout, db
 
 
+def _parse_readout_ts(raw: str):
+    value = (raw or "").strip()
+    if not value:
+        return None
+    if value.endswith("Z"):
+        value = value[:-1]
+    try:
+        parsed = datetime.fromisoformat(value)
+    except ValueError:
+        return None
+    if parsed.tzinfo is not None:
+        parsed = parsed.astimezone(timezone.utc).replace(tzinfo=None)
+    return parsed
+
 def create_app():
     app = Flask(__name__)
 
@@ -78,6 +92,45 @@ def create_app():
             }
         ), 201
 
+    @app.route("/api/sensors/<int:sensor_id>/readouts/range")
+    def api_sensor_readouts_range(sensor_id):
+        sensor = db.session.get(Sensor, sensor_id)
+        if not sensor:
+            return jsonify({"error": "sensor not found"}), 404
+
+        from_raw = request.args.get("from")
+        to_raw = request.args.get("to")
+        from_ts = _parse_readout_ts(from_raw) if from_raw else None
+        to_ts = _parse_readout_ts(to_raw) if to_raw else None
+        if from_ts is None or to_ts is None or to_ts < from_ts:
+            return jsonify({"error": "from and to are required and valid"}), 400
+
+        rows = (
+            db.session.query(
+                SensorReadout.id,
+                SensorReadout.sensor_id,
+                SensorReadout.type,
+                SensorReadout.value,
+                SensorReadout.timestamp,
+            )
+            .filter(SensorReadout.sensor_id == sensor_id)
+            .filter(SensorReadout.timestamp >= from_ts, SensorReadout.timestamp < to_ts)
+            .order_by(SensorReadout.timestamp)
+            .all()
+        )
+        return jsonify(
+            [
+                {
+                    "id": row[0],
+                    "sensor_id": row[1],
+                    "type": row[2],
+                    "value": row[3],
+                    "timestamp": row[4].isoformat() + "Z",
+                }
+                for row in rows
+            ]
+        )
+
     # --- API: dashboard reads (public on the local machine) ---
 
     @app.route("/api/sensors/<int:sensor_id>/types")

server/sensors_client.py

@@ -62,6 +62,11 @@ class SensorsClient:
     def sensor_readouts(self, sensor_id, params=None):
         return self._request("GET", f"/api/sensors/{sensor_id}/readouts", params=params)
 
+    def sensor_readouts_range(self, sensor_id, params=None):
+        return self._request(
+            "GET", f"/api/sensors/{sensor_id}/readouts/range", params=params
+        )
+
     def sensor_readouts_hourly(self, sensor_id, params=None):
         return self._request(
             "GET", f"/api/sensors/{sensor_id}/readouts/hourly", params=params

server/static/retro.css

@@ -491,3 +491,37 @@ textarea {
     letter-spacing: 0;
 }
 .clipboard-delete-form button:hover { background: var(--mc-red-bright); }
+
+/* --- Calendar --- */
+.calendar-controls { display: flex; gap: 0.8em; align-items: center; margin-top: 0.5rem; }
+.calendar-title-row { display: flex; align-items: center; justify-content: space-between; gap: 0.8em; margin-top: 0.5rem; }
+.calendar-grid { display: flex; flex-direction: column; gap: 0.4em; margin-top: 1rem; }
+.calendar-week { display: grid; grid-template-columns: repeat(7, 1fr); gap: 0.4em; }
+.calendar-day { border: 2px solid var(--mc-dim); background: var(--mc-deep); min-height: 6em; padding: 0.3em; width: 100%; box-sizing: border-box; }
+.calendar-day-outside { opacity: 0.55; }
+.calendar-day-header { color: var(--mc-yellow); text-transform: uppercase; letter-spacing: 1px; font-size: 0.8em; }
+.calendar-readouts { list-style: none; padding: 0; margin: 0.3em 0 0; }
+.calendar-event { border-bottom: 1px dashed var(--mc-dim); padding: 0.15em 0; font-size: 0.9em; }
+.calendar-event-time { color: var(--mc-cyan); margin-right: 0.4em; }
+.calendar-event-sensor { color: var(--mc-bright); }
+.calendar-event-type { color: var(--mc-dim); }
+.calendar-event-value { float: right; color: var(--mc-yellow); }
+.calendar-list { list-style: none; padding: 0; margin: 1rem 0; }
+.calendar-day-item { border: 2px solid var(--mc-dim); background: var(--mc-deep); margin: 0.5rem 0; padding: 0.4em 0.6em; min-height: 6em; width: 100%; box-sizing: border-box; }
+.calendar-nav { display: flex; gap: 0.8em; margin-top: 0.8rem; }
+.calendar-today {
+    display: inline-block;
+    text-transform: uppercase;
+    letter-spacing: 2px;
+    background: var(--mc-yellow);
+    color: var(--mc-black);
+    box-shadow: 4px 4px 0 var(--mc-black);
+    padding: 0.4em 1.2em;
+    text-decoration: none;
+}
+.calendar-today:hover { background: var(--mc-cyan); color: var(--mc-black); }
+.calendar-day.calendar-today,
+.calendar-day-item.calendar-today {
+    background: var(--mc-deep);
+    border: 3px solid var(--mc-yellow);
+}

server/templates/calendar.html

@@ -0,0 +1,96 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Calendar — Yggdrasil</title>
+    <link rel="preconnect" href="https://fonts.googleapis.com">
+    <link href="https://fonts.googleapis.com/css2?family=VT323&display=swap" rel="stylesheet">
+    <link rel="stylesheet" href="{{ url_for('static', filename='retro.css') }}">
+</head>
+<body>
+    <nav>
+        <a href="{{ url_for('home') }}">Home</a>
+        <a href="{{ url_for('sensors_page') }}">Sensors</a>
+        <a href="{{ url_for('notes_page') }}">Notes</a>
+        <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
+        <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
+        <a href="{{ url_for('api_docs') }}">API</a>
+        <a href="{{ url_for('logout') }}">Log out</a>
+        <img class="nav-logo" src="{{ url_for('static', filename='yggdrasil-logo.png') }}" alt="Yggdrasil logo">
+    </nav>
+    <h1>Calendar</h1>
+
+    <div class="panel">
+        <h2>Readouts</h2>
+        <div class="calendar-controls">
+            <a href="{{ url_for('calendar_page', view='month', year=year, month=month) }}"><span class="mc-key">M</span>Month</a>
+            <a href="{{ url_for('calendar_page', view='week', date=today.isoformat()) }}"><span class="mc-key">W</span>Week</a>
+            {% if view == 'month' %}
+            <a class="calendar-today" href="{{ url_for('calendar_page', view='month', year=today.year, month=today.month) }}"><span class="mc-key">T</span>Today</a>
+            <a href="{{ url_for('calendar_page', view='month', year=prev_year, month=prev_month) }}">&lt;</a>
+            <a href="{{ url_for('calendar_page', view='month', year=next_year, month=next_month) }}">&gt;</a>
+            {% else %}
+            <a class="calendar-today" href="{{ url_for('calendar_page', view='week', date=today.isoformat()) }}"><span class="mc-key">T</span>Today</a>
+            {% endif %}
+        </div>
+        {% if view == 'month' %}
+        <div class="calendar-title-row">
+            <h2 class="calendar-title">{{ month_label }}</h2>
+        </div>
+
+        <div class="calendar-grid">
+            {% for week in month_weeks %}
+            <div class="calendar-week">
+                {% for day in week %}
+                <div class="calendar-day{% if not day.in_month %} calendar-day-outside{% endif %}{% if day.date == today %} calendar-today{% endif %}">
+                    <div class="calendar-day-header">{{ day.date.strftime("%a %d %b") }}</div>
+                    <ul class="calendar-readouts">
+                        {% for r in day.readouts %}
+                        <li class="calendar-event">
+                            <span class="calendar-event-time">{{ r.timestamp.strftime("%H:%M") }}</span>
+                            <span class="calendar-event-sensor">{{ sensor_names[r.sensor_id] }}</span>
+                            <span class="calendar-event-type">{{ r.type }}</span>
+                            <span class="calendar-event-value">{{ r.value|round(1) }}</span>
+                        </li>
+                        {% endfor %}
+                    </ul>
+                </div>
+                {% endfor %}
+            </div>
+            {% endfor %}
+        </div>
+        {% else %}
+        <div class="calendar-title-row">
+            <h2 class="calendar-title">Tydzień {{ week_start }} – {{ week_end }}</h2>
+            <div class="calendar-nav">
+                <a href="{{ url_for('calendar_page', view='week', date=week_prev.isoformat()) }}">&lt;</a>
+                <a href="{{ url_for('calendar_page', view='week', date=week_next.isoformat()) }}">&gt;</a>
+            </div>
+        </div>
+        <ul class="calendar-list">
+            {% for day in days %}
+            <li class="calendar-day-item{% if day.date == today %} calendar-today{% endif %}" id="calendar-{{ day.date }}">
+                <div class="calendar-day-header">{{ day.date.strftime("%Y-%m-%d (%a)") }}</div>
+                <ul class="calendar-readouts">
+                    {% for r in day.readouts %}
+                    <li class="calendar-event">
+                        <span class="calendar-event-time">{{ r.timestamp.strftime("%H:%M") }}</span>
+                        <span class="calendar-event-sensor">{{ sensor_names[r.sensor_id] }}</span>
+                        <span class="calendar-event-type">{{ r.type }}</span>
+                        <span class="calendar-event-value">{{ r.value|round(1) }}</span>
+                    </li>
+                    {% endfor %}
+                </ul>
+            </li>
+            {% endfor %}
+        </ul>
+        {% endif %}
+    </div>
+
+    <footer class="statusbar">
+        <span>{{ user.username }}@yggdrasil:~/calendar$</span>
+    </footer>
+</body>
+</html>

server/templates/clipboard.html

@@ -14,6 +14,7 @@
         <a href="{{ url_for('sensors_page') }}">Sensors</a>
         <a href="{{ url_for('notes_page') }}">Notes</a>
         <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
         <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
         <a href="{{ url_for('api_docs') }}">API</a>
         <a href="{{ url_for('logout') }}">Log out</a>

server/templates/docs.html

@@ -14,6 +14,7 @@
         <a href="{{ url_for('sensors_page') }}">Sensors</a>
         <a href="{{ url_for('notes_page') }}">Notes</a>
         <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
         <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
         <a href="{{ url_for('api_docs') }}">API</a>
         <a href="{{ url_for('logout') }}">Log out</a>

server/templates/home.html

@@ -14,6 +14,7 @@
         <a href="{{ url_for('sensors_page') }}">Sensors</a>
         <a href="{{ url_for('notes_page') }}">Notes</a>
         <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
         <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
         <a href="{{ url_for('api_docs') }}">API</a>
         <a href="{{ url_for('logout') }}">Log out</a>
@@ -29,9 +30,10 @@
             <li><a href="{{ url_for('notifications_page') }}"><span class="mc-key">3</span>Notifications{% if unread_notifications %} ({{ unread_notifications }} new){% endif %}</a></li>
             <li><a href="{{ url_for('api_docs') }}"><span class="mc-key">4</span>API — documentation</a></li>
             <li><a href="{{ url_for('clipboard_page') }}"><span class="mc-key">5</span>Clipboard — upload and share files</a></li>
+            <li><a href="{{ url_for('calendar_page') }}"><span class="mc-key">6</span>Calendar — sensor readings</a></li>
             <li><a href="{{ url_for('logout') }}"><span class="mc-key">0</span>Log out</a></li>
         </ul>
-        <p class="hint">Tip: press <b>1</b>, <b>2</b>, <b>3</b>, <b>4</b>, <b>5</b> or <b>0</b> to navigate.</p>
+        <p class="hint">Tip: press <b>1</b>, <b>2</b>, <b>3</b>, <b>4</b>, <b>5</b>, <b>6</b> or <b>0</b> to navigate.</p>
     </div>
     <img class="logo" src="{{ url_for('static', filename='yggdrasil-logo.png') }}" alt="Yggdrasil logo">
     <footer class="statusbar">
@@ -50,6 +52,7 @@
                 '3': "{{ url_for('notifications_page') }}",
                 '4': "{{ url_for('api_docs') }}",
                 '5': "{{ url_for('clipboard_page') }}",
+                '6': "{{ url_for('calendar_page') }}",
                 '0': "{{ url_for('logout') }}"
             };
             if (targets[e.key]) window.location.href = targets[e.key];

server/templates/notes.html

@@ -14,6 +14,7 @@
         <a href="{{ url_for('sensors_page') }}">Sensors</a>
         <a href="{{ url_for('notes_page') }}">Notes</a>
         <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
         <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
         <a href="{{ url_for('api_docs') }}">API</a>
         <a href="{{ url_for('logout') }}">Log out</a>

server/templates/notifications.html

@@ -14,6 +14,7 @@
         <a href="{{ url_for('sensors_page') }}">Sensors</a>
         <a href="{{ url_for('notes_page') }}">Notes</a>
         <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
         <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
         <a href="{{ url_for('api_docs') }}">API</a>
         <a href="{{ url_for('logout') }}">Log out</a>

server/templates/sensors.html

@@ -15,6 +15,7 @@
         <a href="{{ url_for('sensors_page') }}">Sensors</a>
         <a href="{{ url_for('notes_page') }}">Notes</a>
         <a href="{{ url_for('clipboard_page') }}">Clipboard</a>
+        <a href="{{ url_for('calendar_page') }}">Calendar</a>
         <a href="{{ url_for('notifications_page') }}">Notifications{% if unread_notifications %} <span class="nav-badge">{{ unread_notifications }}</span>{% endif %}</a>
         <a href="{{ url_for('api_docs') }}">API</a>
         <a href="{{ url_for('logout') }}">Log out</a>

server/tests/test_split_apps.py

@@ -279,6 +279,34 @@ class MainAppTest(unittest.TestCase):
             self.assertEqual(Notification.query.filter_by(id=first_id).count(), 0)
             self.assertEqual(Notification.query.filter_by(id=second_id).count(), 1)
 
+    def test_calendar_requires_login(self):
+        response = self.client.get("/calendar")
+        self.assertEqual(response.status_code, 302)
+        self.assertIn("/login", response.headers["Location"])
+
+    def test_calendar_month_and_week_views_render(self):
+        self.login()
+        month_response = self.client.get("/calendar?view=month")
+        self.assertEqual(month_response.status_code, 200)
+        self.assertIn("Calendar", month_response.get_data(as_text=True))
+
+        week_response = self.client.get("/calendar?view=week")
+        self.assertEqual(week_response.status_code, 200)
+        self.assertIn("Calendar", week_response.get_data(as_text=True))
+
+    def test_calendar_readouts_range_endpoint(self):
+        self.login()
+        sensor_id = self.create_sensor_and_readout("calendar-test")
+
+        response = self.client.get(
+            f"/api/sensors/{sensor_id}/readouts/range"
+            "?from=2000-01-01T00:00:00&to=2100-01-01T00:00:00"
+        )
+        self.assertEqual(response.status_code, 200)
+        data = response.get_json()
+        self.assertEqual(len(data), 1)
+        self.assertEqual(data[0]["sensor_id"], sensor_id)
+
     def test_notes_require_login(self):
         response = self.client.get("/notes")
         self.assertEqual(response.status_code, 302)