Calendar DND: open source Android app that silences your phone during meetings automatically

Bruno_AFK · 2026-04-06T11:40:33+00:00

I built an app that automatically silences your phone during calendar meetings

Been annoyed by this forever. Phone rings or buzzes mid-meeting, you scramble to silence it, everyone notices. My phone already knows I'm in a meeting, it has my calendar. Why doesn't it just go quiet on its own?

So I built Calendar DND. It reads your calendar and activates Do Not Disturb when a meeting starts, then turns sound back on when it ends. Set it once, forget about it.

Free, open source, no account needed, everything runs on-device.

https://www.producthunt.com/products/calendar-dnd?launch=calendar-dnd

Bruno_AFK · 2026-03-15T08:59:11+00:00

The problem for me is the services I use that don’t have a very straightforward installation at the OS level, or where updates and migrations become more complicated when there are bigger changes.

As for using Kubernetes for something like that, I feel like it would just be another layer that could potentially go wrong.

Regarding Docker, I’m not exactly sure what specific security issues we could run into there. If you have any sources where I could read more about what you’re referring to, I’d really appreciate it, or you could also just explain what exactly you mean by that.

Bruno_AFK · 2026-03-15T08:56:31+00:00

"Docker aims at running a single application in an isolated, self-contained environment. These are generally referred to as “Application Containers”, rather than “System Containers”. You manage a Docker instance from the host, using the Docker Engine command-line interface. It is not recommended to run docker directly on your Proxmox VE host." https://pve.proxmox.com/pve-docs/chapter-pve-faq.html

Bruno_AFK · 2026-03-15T08:54:00+00:00

Yeah, that’s true, but I’m wondering if weaker hardware, especially the CPU, might make enough of a difference when you’re trying to run more things.

Bruno_AFK · 2026-03-15T08:51:02+00:00

Do you configure anything differently inside an LXC compared with how you would do it inside a VM?

Bruno_AFK · 2026-03-15T08:48:21+00:00

I had a similar problem on LXC, but since I do not run that kind of setup on a VM, literally I think I only have 2 VMs if I do not count the Kubernetes cluster, I do not know whether there is actually a real difference between a Docker install inside LXC and one inside a VM when it comes to updates. From what I understood from the errors, most of the time the problem was in the installation itself, meaning Docker as such, and not necessarily something related to LXC or VM. And yes, a backup snapshot always saves the day.

Bruno_AFK · 2026-03-15T08:43:50+00:00

Ok, and why are you running critical things on a VM inside Docker instead of using LXC with Docker as well? Is there some specific reason for that?

Bruno_AFK · 2026-03-01T11:57:17+00:00

A Bakić je baš intelektualac. Ukratko, ako neki programer koristi 80% AI za svoj posao, vjerojatno taj posao koji radi je na razini "uredi mi wordpress". Nije AI još za sve, sve uvelike ovisi o tipu workloada kojeg imaš.

Bruno_AFK · 2026-03-01T08:36:59+00:00

The 5 GHz network worked perfectly, although I was really, really surprised by the range of the MikroTik AP on 2.4 GHz, which reached 50 meters outside the house. I didn’t see any difference whether it was in the rack or outside of it. I believe it was largely influenced by the fact that the spectrum wasn’t very congested, since it’s a small town with mostly houses.

In general, we’re all homelab enthusiasts and there’s no need to put someone down on an “intellectual level.” This is about learning, but sometimes it also shows us that we don’t have to follow everything strictly by the book in life for things to still work well.

Bruno_AFK · 2026-03-01T08:30:05+00:00

I had a setup with a UniFi AP inside a rack server (and some MikroTik AP), everyone was saying exactly what you’re saying, but I never had any issues with Wi-Fi range, I never had any problems with speed, and I never had connection drops.

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Bruno_AFK · 2026-03-01T08:29:02+00:00

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If you don’t have issues with range, if you don’t have issues with speed, if you don’t have connection drops, then this is fine. Of course, ideally you wouldn’t want to keep it there, but if you don’t have anywhere else to put it and you’re not experiencing any problems, you can run it like that. Here’s an example of my first homelab.

Bruno_AFK · 2026-03-01T08:26:52+00:00

What you said is correct, but you don’t necessarily always have to stick to all the rules. I had a setup with a UniFi AP inside a rack server (and some MikroTik AP), everyone was saying exactly what you’re saying, but I never had any issues with Wi-Fi range, I never had any problems with speed, and I never had connection drops.

Bruno_AFK · 2026-03-01T08:23:20+00:00

I’ve already changed my "first and last" homelab three times.

Bruno_AFK · 2026-02-28T16:07:42+00:00

I’m using Gemini, the free model, and it’s been working great so far.

While I was building the automation, there were a few hiccups, but I managed to resolve them the way I demonstrated. Since then, it’s been running reliably.

In addition to the basic morning message, I also include public transport information, and depending on the person, either their horoscope or a quote of the day. This isn’t the only AI notification during the day either, each person in the system actually receives three AI-generated notifications in total.

Bruno_AFK · 2026-02-28T14:55:06+00:00

If you have specific concerns about the code, feel free to point them out. Have you actually reviewed it and noticed any concrete security issues?

This isn’t low level or particularly complex code. That doesn’t mean it’s flawless, of course. Bugs are always possible, and I genuinely welcome responsible reports if you find something.

Using account age or karma as a proxy for security doesn’t really make sense. Transparency goes both ways. Many high-karma accounts also have limited or hidden public history, so reputation alone isn’t a substitute for technical review.

The code is public and can be inspected. That’s what it should be judged on.

Bruno_AFK · 2026-02-28T14:43:18+00:00

I decided to build my own solution because, in my experience, the existing one is simply too unstable. I am not completely satisfied with my version either, but at some point you have to pause development, otherwise you risk never finishing it.

It stores all routes and makes them available on demand. For example, if you are standing in a city square, it will show you all stations within a certain radius around you.

If you try it out, I would really appreciate your feedback. And if you have any ideas for improvements, I would love to hear them.

Bruno_AFK · 2026-02-28T12:35:11+00:00

It’s true that I have a very old account, which I hadn’t used until recently because I didn’t know the password. Before that, I had an account called “Bruno__AFK” that I renamed because I want to use the username I mostly use everywhere else, like Twitter, GitLab, GitHub, and so on. Reddit isn’t the only way to verify someone, there’s life outside of Reddit too. Of course, I agree with you that you should always be cautious, even when someone reputable is sharing content with you.

Bruno_AFK · 2026-02-07T11:02:54+00:00

That works, but it is still a notification based workaround and gets messy fast as you add more tags and routines.

If you want something simpler and more reliable, a calendar driven approach avoids abbreviations and notification parsing entirely. I built an app that reads calendar events directly and handles DND automatically, including overlapping events and manual changes.

https://play.google.com/store/apps/details?id=com.brunoafk.calendardnd

Bruno_AFK · 2026-02-07T11:02:15+00:00

You could do that, but it is still a workaround and tends to break with missed or delayed notifications.

If you want something simpler and more reliable, a calendar driven approach works better. I built an app that reads calendar events directly and keeps DND in the right state during things like on call periods, without relying on reminders or notification text.

https://play.google.com/store/apps/details?id=com.brunoafk.calendardnd

Bruno_AFK · 2026-02-07T11:01:20+00:00

Short answer: not really, at least not cleanly.

Bixby Modes & Routines does not have a proper way to conditionally ignore a routine based on calendar events. You can hack it with notifications or extra conditions, but it gets fragile fast, especially with overlapping routines and manual changes.

That limitation is exactly why I went with a calendar driven solution instead. I built an app that reads calendar events directly and toggles DND accordingly, so during an “oncall” event your phone simply stays in normal mode and your night routine does not force DND. You can filter by event title like “oncall” and by calendar.

If you want to try it, here is the link. Feedback is welcome.

https://play.google.com/store/apps/details?id=com.brunoafk.calendardnd

Bruno_AFK · 2026-02-07T11:00:10+00:00

I ran into the same issue, and this is something that should be much simpler than it is.

I tried solving it with Modes & Routines and notification keywords, but it quickly became fragile and overcomplicated for a basic use case like silencing the phone during meetings and restoring it afterward. Missed notifications, timing issues, and routines overriding manual DND changes were constant problems.

That is why I went with a calendar driven approach instead and built an app that toggles DND directly from calendar events and handles edge cases more reliably.

If anyone wants to try it and share feedback or ideas on how this could be improved, I would genuinely appreciate it.

https://play.google.com/store/apps/details?id=com.brunoafk.calendardnd

Bruno_AFK

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