Shared calendar stored in OpenWRT router?


I am using a ZyXEL WSM20 under 23.05.2, and I was wondering if it would be feasible to make it store a calendar shared with my family.


  • calendar easy accessible from different devices (Win/Linux/Android/iOS) when at home or outside
  • able to sync when online (I mean, either a device or the router can be offline, due to network coverage/connection issues/power outage. Can they sync later when everything is up and running, without losing any entry?)
  • A plus: configurable / accessible from Luci

I started thinking about having a shared calendar for my family, wondering if there was a privacy-friendly and free/open solution that could allow the whole family to use all the current devices to check/add/edit appointments and make them visible for the rest of the family ... and I was wondering which kind of service I should look in the internet, that would be compatible with the current calendar app in each device... but some hundreds of entries should not require a large storage space, and I wondered if it could fit in the hardware I already have in place :slight_smile: instead of subscribing to another service.
I still have a lot of questions (can all this work only when everything is online? What if there is a power outage? Can it store locally and sync when online? And so forth), but let's start from the basics... I guess somebody else already worked out a good solution for that

Thank you in advance for your support

1 Like

I wouldn't store the calendar on the router, due to flash wear, and the WSM20 doesn't have an USB port for external storage.

I'd just set up a BS mail account with google, then share the calendar that comes with the account - or
Probably not the best for your privacy, but easy to set up.

I'm sure there are free password protected calendar out there, if you look for one.


HI @frollic
Thank you for the feedback

Fair point.

I guess I will not follow this one, but look for another solution, which surely exists. Anyway, if there are forum users with some other suggestions, don't be shy :slight_smile:

(or e.g. owncloud has a CalDAV server as well).

But I would deploy it e.g. on a Raspberry Pi (e.g. Zero, with or without OpenWRT, depending on your preference) and add it via a DMZ-config interface to OpenWRT, if you do not like cloud-hosted calendars.

There is a file format for Calendar data: *.ics. Most calendar apps can access and import/sync. I suspect this would achieve the same result with less complexity.

Thank you @Pico
Interesting. But if I understood correctly, it would work only locally, not from the internet, right?

Hi @shep

I might have missed the point there, but it is not clear to me how that would be the solution to my case

I don‘t have personal experience about the usafe and security quality of the service.

But if it can be accessed on your private LAN, you could make it accessible via WAN or via VPN as well. All just a matter of on which interface it would listen on and what your firewall and port mapping is told to do.