Ask HN: Software recommendation to keep multiple calendars in sync as freelancer

Any suggestions/software to keep multiple calendars from multiple clients in sync? Currently i've three clients, two with Office365, one with Gsuite plus my private one. I find myself constantly going through three web views, making or accepting one appointment and creating a blocker in the other two. Running on Linux, a big plus would be that the credentials won't leave my system. I won't mind using e.g. a private google account as "master" to merge and distribute the calendars as long as the others would only see "blocker" and not the details of the actual appointment.

20 points | by rivert 992 days ago

8 comments

  • cakes 992 days ago
    You may at least want to take a look at vdirsyncer[0]. Assuming all of your sources run CalDAV that you can hit than you can at least extract the events. I use it for backup for a calendar of my own (so I don't know what I would use to "merge" multiple synced calendars into a singular view but maybe you could do that via a "master" account an write all the other events to it?)

    [0]http://vdirsyncer.pimutils.org/en/stable/

  • mvdwoord 992 days ago
    Struggled with this in the past as well, and usually run into issues with my clients doing their best to make it hard to export this kind of data from their network.

    Once installed a tool that synced corporate Notes calendar to private google calendar, which I could share with my private google calendar. Found out the hard way, that when Google calendar imports an event, it parses the entire invite for email addresses and re-sends the invite from that private account(!!). This major leak was why I stopped doing it there. Wrote some manual Outlook export and upload to gmail scripts as usually security settings do not allow you to share with calendars outside of your organization.

    Currently it is not an issue for me but from experience, handcrafting a manual solution and sync regularly using your own script seems the way to go. Using a google calendar to mirror every corporate calendar you use, then aggregating those in your own (google) calendar. Problem with all of this is of course direction of sync (i.e. no busy time blocked in corporate calendars).

  • joshuasilver 992 days ago
    https://syncthemcalendars.com/

    Does exactly what you want.

    • g_p 992 days ago
      Unfortunately this service doesn't seem to work with 365-based calendars, or anything other than Gmail/Google workspace.

      Otherwise jt does seem to do what's needed (albeit server-side).

  • yunohn 992 days ago
    You can do this in Google Calendar, by adding the Busy/Free details of your other calendars by sharing them. Not sure if O365 supports that, however.
  • 97-109-107 991 days ago
    I have never fully solved this problem via synchronisation that does a replication/pasting.

    My current solutions is two-fold On Android - Business Calendar subscribes to all On Desktop - Fastmail

    This however does not solve propagation of busy-status to other calendars.

    As far as I understand the caldav standart is cumbersome and often misinterpreted by clients.

  • rivert 991 days ago
    Thanks all for your input. It's a bit buffling that calendars are not a solved problem in 2021. Going down the path of vdirsyncer + davmail with some self written filters to only show blockers (stripped everything else out) seems to be the most sensible way.
  • thepra 992 days ago
    Some Nextcloud instances offer CalDAV, so you could connect this to a client that does support and sync with it. In my case I use Thunderbird with few add-ons to make it possible, on the smartphone I use instead davx5.
  • atonse 992 days ago
    I’m also interested in such a tool since I have something like 6 accounts and would love to have one unified view and also advertise my availability in one unified view.