lillianwang112/tiger-calendar

The calendar app built for Princeton students — course scheduling, academic calendar, cloud sync, and more
Free, ad-free, and made specifically for Princeton life

🚀 Open App • 📖 Quick Start • ❓ FAQ

Hey Everyone! 👋

I built TigerCalendar because Google Calendar doesn't know what a precept is, and iCal doesn't know when Spring Break starts. This is a full-featured calendar and task manager built specifically for Princeton students — with course setup, semester-aware scheduling, academic calendar overlays, cloud sync, and a time grid that actually works on your phone.

⚡️ Quick Start (TL;DR)

Visit lillianwang112.github.io/tiger-calendar
Click "Courses" to set up your semester schedule
Pick your semester (Spring 2026 or Fall 2026)
Add your courses with lecture, precept, lab, and drill times
Hit "Save & Generate" — your whole semester populates automatically 🎉

📱 Install as an App (PWA)

TigerCalendar is a Progressive Web App — install it on your phone or computer for a fullscreen native app experience, no App Store required.

iPhone/iPad (Safari):

Open the app in Safari
Tap the Share button (square with arrow)
Scroll down and tap "Add to Home Screen"
Toggle "Open as Web App" ON
Tap Add — launches fullscreen like a real app!

Android (Chrome):

Open the app in Chrome
Tap the three-dot menu → "Add to Home Screen" or "Install App"

Desktop (Chrome/Edge):

Look for the install icon (⊕) in the address bar
Click "Install"

Your data saves locally and syncs to the cloud if you sign in with Google — so you won't lose anything even after installing.

📤 Export to Google Calendar, Apple Calendar & More

Don't want to switch calendar apps? No problem.

TigerCalendar is also the fastest way to set up any calendar for the Princeton semester. Use the Course Wizard to enter all your courses in under 5 minutes — lectures, precepts, labs, drills, office hours, exams, and problem set deadlines — with Princeton's academic calendar (spring break, midterm week, finals) all pre-loaded and handled automatically. Then export everything as a standard .ics file and import it directly into Google Calendar, Apple Calendar, Outlook, or any other app.

The workflow:

Set up your full semester schedule in TigerCalendar (~5 min)
Go to Settings → Export .ics
Import the file into your calendar app of choice
Done — your entire semester is populated, breaks skipped, precepts included

Google Calendar doesn't know what a precept is. TigerCalendar does.
Set it up here, take it anywhere.

✨ Features at a Glance

Feature	Description
📅 5 Calendar Views	Day, Week, Month, Year, Schedule
🎓 Course Wizard	Add lectures, precepts, labs & drills with per-day time overrides
🗓️ Princeton Academic Calendar	Breaks, midterm week, finals, and more — auto-loaded
🔁 Recurring Events	Daily, weekly, monthly, annually, weekdays, or fully custom
📋 Relative Assignment Generator	Auto-generate a full semester of pset deadlines tied to your course schedule
✅ Exams & Assignments Tracker	Deadlines, problem sets, and exams per course — with relative auto-generation
🗂️ Syllabus View	Auto-generated timeline of all lectures, precepts, labs, and drills per course
📚 Study Block Generator	Quickly create recurring study sessions tied to a course
☁️ Google Cloud Sync	Sign in to sync across all your devices in real time
📱 Mobile-Optimized	Long-press-to-drag, pinch-to-zoom, swipe navigation
💯 100% Free	No ads, no paywalls, no subscriptions

🚀 How to Use

Step 1: Open the App

Visit: lillianwang112.github.io/tiger-calendar

Step 2: Set Up Your Courses

Click "Courses" in the top bar
Select your semester (Spring 2026 or Fall 2026)
For each course, enter:
- Course name and color
- Lecture days and times
- Precept, lab, and drill sessions (if applicable)
- Locations for each session type
Click "Save & Generate" — events are created for every class day of the semester, skipping breaks automatically

Pro tip: Use the "Same time every day" toggle if your precept time varies by day of week — you can set per-day overrides!

Step 3: Auto-Generate Your Problem Set Deadlines

One of TigerCalendar's most powerful features: instead of entering each pset deadline manually, use the Relative tab in Exams & More to generate your entire semester's worth of assignments in one step.

Click "Exams & More" in the top bar and select your course
Go to the Relative tab
Set the anchor (e.g., "After each Lecture"), offset in days, due time, and title prefix
Enable auto-numbering (PSET 1, PSET 2, …) and hit Preview → to review
Confirm — every deadline for the semester is created instantly

Step 4: Add Events & Tasks

Left: Click and drag to set duration | Right: Fill in event details

On desktop:

Click any empty time slot to create an event at that time
Click and drag to set start and end time at once

On mobile:

Tap any time slot for a quick preview, then tap again to create
Long-press (hold 300ms) and drag to draw out a duration

For tasks: Use the task type to set a deadline without blocking off calendar time.

Click your profile area and sign in with Google to:

Sync your calendar across your phone, tablet, and laptop
Never lose your schedule if you clear your browser

Step 6: Explore Views

Switch between views using the buttons at the top or keyboard shortcuts:

Week view — the main workhorse; shows your full schedule at a glance
Month view — great for planning ahead
Schedule view — a linear list of upcoming events, perfect on mobile
Day view — zoomed in on a single day
Year view — bird's-eye view of the whole year

✨ All Features

📅 Calendar Views

Day — full time grid for a single day
Week — 7-column time grid with swipe navigation on mobile
Month — traditional grid with color-coded event chips and task dots
Year — compact overview of all 12 months at once, with event indicators
Schedule — chronological list of upcoming events and tasks, perfect on mobile
Now line — live red indicator showing the current time, updates every minute
Mini calendar in sidebar for quick date jumping
Pinch-to-zoom on the time grid to adjust hour height

🎓 Course & Academic Integration

Course setup wizard — configure lectures, precepts, labs, and drills in one place
Per-day time overrides — set different times for, say, Tuesday precept vs. Thursday precept
Semester selector — Spring 2026 and Fall 2026 with all Princeton academic dates pre-loaded
Academic calendar overlay — add/drop deadline, midterm week, spring break, finals, commencement, and more
US Holidays overlay — toggle on/off independently
Auto-generation — skips breaks and non-class days automatically when generating your schedule
Syllabus view — after course setup, the Exams & More modal shows a full auto-generated timeline of every lecture, precept, lab, and drill session for the semester, with exact dates and locations

📝 Events & Tasks

All-day events with multi-day span support
Recurring events — daily, weekly (with specific days), monthly, annually, every weekday, or fully custom (every N days/weeks/months/years, with specific days-of-week and configurable end conditions: never, by date, or after N occurrences)
Location field — shown inline on the time grid
Notes field — for details, readings, or links
Tasks — separate from events, with a due date and optional due time; overdue tasks are highlighted
Drag-to-reschedule — move events by dragging on desktop
Click and drag to create — drag across a time range to set start and end time at once
Undo — Cmd/Ctrl+Z to undo any change

📊 Exams, Assignments & Office Hours Tracker

All accessible from the Exams & More button in the top bar, organized per course across five tabs:

Exams — log quizzes, midterms, finals, oral exams, and practicals with date, time, location, and study notes
Assignments — log individual problem sets and assignments with due date, due time (to the minute), tags, estimated hours, and details
Office Hours — add recurring office hours with instructor/TA name, days of week, time, and location; automatically appear under the "Office Hours" sidebar category
Relative — automatically generate a full assignment series tied to your course schedule (e.g., "Problem Set due 0 days after each Lecture at 11:59 PM"), with auto-numbering (PSET 1, PSET 2, …) and a live preview before committing — saves significant setup time at the start of the semester
Syllabus — browse the complete auto-generated list of all course sessions (lectures, precepts, labs, drills) with dates and locations, as a quick reference

📚 Study Block Generator

Quickly create recurring study sessions tied to a specific course
Set a label (e.g., "Study"), choose days of the week, and set start/end times
Appears on the calendar with the course's color for at-a-glance weekly planning

🗂️ Sidebar & Filtering

Upcoming panel — scrollable list of events and tasks for the next few days, grouped by date
Category filtering — toggle any category or course on/off to declutter your view; each course gets its own toggle chip
Time Insights — total hours scheduled this week, broken down by course with named colored bars (e.g., MAT 217: 4.0h, COS 126: 4.0h)
Weekly load chart — bar chart visualizing your event density by day of the week, broken down by type (Class, Exam, Work) to quickly spot busy vs. light days
Tasks panel — toggle between Tasks, Events, or Both in the sidebar; tasks show completion state and undo support

☁️ Sync & Persistence

localStorage — all data saved locally in your browser automatically, no sign-in required
Google account sync via Firebase — sign in with Google to back up and sync across all your devices in real time; a "Syncing across devices" indicator confirms active sync in your account panel
Offline-capable — works without an internet connection once the page has loaded (service worker caching)
Export/Import — download your data as an .ics file (compatible with Google Calendar, Apple Calendar, and Outlook) or as JSON; import JSON back on any device

📱 Mobile & Touch

Swipe navigation — swipe left/right in week/day view to move forward or back
Long-press-to-drag — hold 300ms on an empty time slot, then drag to set duration (no accidental scroll triggers)
Tap-to-preview — tap an empty slot to see a "New event" preview before committing
Pinch-to-zoom — spread or pinch on the time grid to adjust hour height
FAB — floating action button on mobile for quick event creation
Responsive sidebar — collapses automatically on small screens
Install as PWA — add to your home screen on iOS (Safari → Share → Add to Home Screen) or Android/Desktop (Chrome → Install App) for a fullscreen native app experience, no App Store required

🎨 Personalization

Theme accent colors — choose from 5 accent colors (Purple, Orange, Green, Blue, Rose)
Light/Dark mode — toggle between light and dark themes
Week start day — Sunday or Monday
Color-coded courses — each course gets a unique color automatically, fully customizable
Custom categories — create your own beyond the built-ins (Personal, Other)
Time format — 12-hour or 24-hour
Timezone — configurable (defaults to America/New_York)

⌨️ Keyboard Shortcuts

Key	Action
`D`	Day view
`W`	Week view
`M`	Month view
`Y`	Year view
`S`	Schedule view
`T`	Jump to today
`←` / `→`	Navigate forward / back
`N`	New event
`\`	Toggle sidebar
`Cmd/Ctrl + Z`	Undo last action

❓ Frequently Asked Questions

🚀 Getting Started

Do I need to make an account?

Nope! TigerCalendar works fully without signing in — your data is saved automatically in your browser. Sign in with Google only if you want to sync across multiple devices.

Does this work on my phone?

Yes! It's fully touch-optimized with swipe navigation, long-press-to-drag, and pinch-to-zoom. Install it as a PWA for the best experience — it'll feel just like a native app.

Can I use this offline?

Yes! Once the page loads, the app works without an internet connection. A service worker caches everything locally.

Which semesters are supported?

Spring 2026 and Fall 2026 are built in, with all Princeton academic dates pre-loaded. More semesters will be added as they're announced.

📅 Courses & Events

How do I add a course with different precept times on different days?

In the course wizard, turn off the "Same time every day" toggle for the precept section. You'll be able to set a different time for each day of the week that precept meets.

How do I auto-generate all my problem set deadlines at once?

Go to Exams & More, select your course, and click the Relative tab. Set the anchor (e.g., "After each Lecture"), offset in days, due time, assignment type, and title prefix. Enable auto-numbering and hit Preview → to review before generating. This creates the full semester's worth of assignments in one step.

How do I edit or delete an event?

Click any event to open it. You'll see Edit and Delete buttons. For recurring events, you can delete just that occurrence or the whole series. Note: editing a single occurrence of a recurring event is not yet supported.

Can I add events that aren't courses?

Yes! Use the Personal or Other categories for non-course events, or create your own custom categories with any color.

Can I see my tasks alongside my events?

Yes. Tasks with due dates appear in the all-day row in week/day view and in the sidebar upcoming panel. Overdue tasks are highlighted.

☁️ Sync & Data

My data disappeared after I cleared my browser!

Data is stored in your browser's local storage by default. Clearing browser data will erase it. To prevent this, sign in with Google for cloud backup — or use Export in Settings to download a JSON copy of your data regularly.

Can I use TigerCalendar on my laptop and phone at the same time?

Yes, if you sign in with the same Google account on both devices. Changes sync in real time via Firebase, and the Account panel will show a "Syncing across devices" confirmation.

Can I export my calendar to Google Calendar or Apple Calendar?

Yes! Go to Settings → Export .ics to download a standard iCalendar file you can import into Google Calendar, Apple Calendar, Outlook, or any other calendar app.

🛠️ Tech

Zero build step. Single index.html — just open it in a browser.

React 18 via CDN — no npm, no bundler
Babel Standalone — for in-browser JSX compilation
Firebase Auth & Firestore — optional Google sign-in and real-time cloud sync
Google Fonts — DM Serif Display, DM Mono, DM Sans
localStorage — offline-first persistence
Service Worker — PWA caching and offline support

🙏 About This Project

TigerCalendar was built by a Princeton student who got tired of manually entering every precept into Google Calendar and then manually blocking off spring break. It started as a weekend project and grew from there.

Note: The app is still a work in progress and may have bugs. If you find any issues or have feature suggestions, please reach out at lw3319@princeton.edu — feedback genuinely helps!

The app is open source and free to use or adapt. If you find it useful, share it with your classmates!

Good luck this semester. Go Tigers! 🐯

🚧 Known Limitations & Future Ideas

Current Limitations

localStorage only (without sign-in) — clearing browser data will erase local progress; sign in with Google or export regularly to be safe
No cross-device sync without Google sign-in — data lives in the browser unless you're signed in
Recurring event edits — editing a single occurrence of a recurring event isn't yet supported (only delete)
No push notifications — no reminders for upcoming events yet

Possible Future Features (Maybe!)

🔔 Push notifications / reminders
📲 Two-way Google Calendar sync
🗺️ Campus map integration for locations
📊 Semester-level workload analytics
🤝 Share your schedule with friends

Note: This is a student project maintained during the semester. Updates may be sporadic!