Is there a free, open source appointment scheduling-system similar to Calendly where I can predetermine timeslots for others to choose?
And if one person selected a timeslot, then that timeslot is visible as reserved or blocked for others.
I would like to have a self-hosted alternative to Calendly, perhaps based on PHP/MySQL.
I already tried Easy!Appointments, but a "dependency hell" (via NodeJS / npm) made me download an additional 32.000 documents (!), which in turn led to errors during the more-than-an-hour-long FTP upload, which ultimately meant that I could not use it.