Hosting our own calendar, to be shared within a team? [closed]

I work in a small (3 people) team and we need to be able to share our calendar i.e. to see periods when we are busy/free perhaps to organise meetings and so on.

Outlook and Exchange is not an option.

I know about Google Calendar but I would prefer a tool we can host on our server (preferably PHP + MySQL).

Any suggestions?

I recommend Knutsen's WebCalendar - I've been using it for years. It's all PHP & MYSQL; completely open source. It's completely configurable. Everyone I've suggested to has adopted it.

I've done a lot of research for my own uses, and I revisit the options every now and then. What I've found is most of the calendaring solutions out there are actually pretty awful. It turns out that shared calendaring is really hard.

I originally went with Google Calendar, and I much prefer it. Now I use Google Apps since I got a domain. I like that it is hosted for me so I don't have to deal with the administration of the software and the service. Sure, it might be down sometimes, but I'm getting the service for "free" (advertising and information selling aside :-)). I know of a lot of tech companies with the manpower to setup/build their own solutions that use Google Apps because outsourcing the maintenance to Google frees up their IT staff to add more value.

That said, Zimbra includes a calendaring option in addition to providing email. I would stay away from Microsoft's products and their high priced per-client access, same with any of the large commercial offerings.

The open standard for calendaring is CalDAV (RFC4791). Hopefully you can find a server and client to suit you (also see DAViCal server's client list).