Calendar0
Siri for your calendar, but it actually works
Hey IH! 👋
I just came up for air after the most intense 2-week sprint I've had building Calendar0 (my menubar calendar app with AI).
The TLDR:
✅ Microsoft Outlook integration (full CRUD + webhooks)
✅ Complete UI/UX redesign with drag-and-drop timeline
✅ Multi-calendar support (read from all, write to one)
✅ Automated blog system
✅ Landing page redesign
✅ 110+ files modified, +2,000 lines of code
What triggered this sprint?
A user emailed: "Why doesn't this work with my work Outlook calendar?"
That simple question snowballed into:
1. "I should add Microsoft support" → 280 lines of provider code
2. "Wait, people have multiple calendars" → multi-calendar architecture
3. "The UI doesn't show this well" → complete day view redesign
4. "I should show this progress" → blog system + automation
The biggest win: Drag-and-drop timeline view
Before: Simple list of events
After: Visual hourly timeline where you can drag events to reschedule
The hardest part: Microsoft's API is... different
Google Calendar: Clean, well-documented, consistent
Microsoft Graph: 3 different date formats, weird recurrence patterns, Teams links everywhere
Spent 6 hours debugging why all-day events were showing as 12 AM...
What I learned:
1. Scope creep can be good - Each feature naturally led to the next improvement
2. Refactor first, add features second - The multi-provider abstraction made Microsoft integration 10x easier
3. Users don't see the code, they see the value - Nobody cares about my clean architecture, they care about Outlook support
The metrics:
Code: 110+ files touched, +2,000 net LOC
Time: ~14 days of focused work
Coffee: Too much ☕
Sleep: Not enough 😅
Now I'm wondering:
Should I slow down and focus on polish, or keep this momentum and add Apple Calendar next?
What's your experience with "build fast" vs "build perfect"?
If you want to try it: calendar0.app (macOS & Windows, Microsoft Store available)
Would love any feedback on the approach or the product itself!
Calendar0 is a desktop app that lives in your system tray. Click once to see all your calendars. Type "lunch with sarah tomorrow" and it schedules the meeting. It finds Sarah's email, checks availability, sends the invite.
Calendar0 is:
A system tray app - View your calendar instantly without opening a browser
An AI assistant - Manage everything in your calendar using natural language commands
Smart contact resolution - Automatically converts names to emails using Google Workspace and checks all attendees' availability before booking
One-click meeting access - Smart notifications let you join meetings instantly
Current Status
Launch week: Just went live 2 days ago
Users: 3 paid customers
Revenue: $1938 (lifetime deals at $19)
Time to build: 2 months of nights/weekends
Tech Stack
Frontend: Electron
AI: Gemini 2.5 Flash API for natural language
Backend: Google Calendar API, OAuth
Pricing Strategy
Launching with a founding member deal:
Completely free calendar view
Lifetime for AI assistant: $19 (limited to 500 users)
Monthly: $2.99
Free trial: 3 AI commands to experience the magic
The lifetime deal is intentionally underpriced to get early users who'll help shape the product.
Check it out at calendar0.app.
Would love your brutally honest feedback.
Thank you!
-
1
Looks awesome! Love the simplicity and the “type to schedule” idea — feels super natural. The lifetime deal is smart for early traction. Congrats on launching, and props for building this in just 2 months!
-
1
Thank you!
-
-
1
Whoa, Calendar0 nails it: "Siri for your calendar, but it actually works." Voice-activated scheduling without the rage-quits? As an indie hacker juggling 17 tabs and zero patience for clunky apps, this feels like magic. Beta sign-up was a breeze—already blocked out my next launch sprint hands-free. Total time-saver at launch price. If Siri ghosts your events one more time, jump on this. What's your go-to calendar hack?
-
1
Thank you for your feedback! Every day I block deep work sessions to avoid interruptions. This helped a lot over time to get things done
-
-
1
Amazing! I love the minimal UX and the focus on the user issues. The natural language scheduling is really cool. Do you expect to add Apple Calendar anytime soon? Would be important for me to use it (: I really love the idea
-
1
Thanks so much for your feedback!
Yes, I am planning to add support for Apple Calendar very soon!
-
-
1
This looks super clean and focused. Love how you kept the UX minimal and built something directly around user behavior (‘checking your calendar 30+ times a day’ is so relatable). The Gemini integration for natural language scheduling is a smart move too — feels like a mini Copilot for meetings. Curious: are you planning to expand beyond Google Workspace (like Outlook or Notion integrations) later on
-
1
Thank you for your feedback!
Yes I am planning to add M365, Exchange and Apple Calendar support. Besides many other features too!
-
-
1
Love the idea of the founding $19 fee. I'm going to use this as well. I'm curious how you got feedback from the customers on why they chose your product over others?
-
2
Thank you!
The most appreciated feature is the check for availability on others calendars too before booking
-
-
1
This is a genius execution. I love how Calendar0: 1) sits in the system tray for instant access,2) turns natural language commands into automated scheduling, and 3) smartly resolves emails with Google Workspace. That lifetime $19 founding member deal is textbook early-adopter strategy—super smart for traction under budget. Founders can apply the same “micro-effort, max-output” logic for any SaaS launch to get early users engaged.
From a CRO and onboarding copy perspective, highlighting the free 3-command trial upfront in the micro-copy and adding a tooltip showing “one-click join” could instantly boost trial-to-paid conversion and retention. These tweaks tie directly into messaging optimization and high-LTV funnels, which is exactly where I help founders hit 999-level conversions.
If you want, I can do a free 2-step messaging & onboarding audit showing how to map your tray UX + AI assistant into copy that drives $100+/user LTV. DM me, and I’ll break it down step-by-step.
-
1
Thank you!
-
Comment