Google Calendar has a built in Appointments feature if you're using Google
for Work or Google for Education (but not Plain Old Google). If you can
embed a calendar in an iframe you could embed the resulting appointment
slot view, or just link out to it if you'd rather not (or can't) iframe.

Google Calendar appointments I think can do everything on your feature list.

On Thu, Oct 26, 2017 at 3:14 PM, Karlsen, Jeffrey <[log in to unmask]>
wrote:

> We need to look at new options for appointment scheduling/booking since
> our current cloud solution (youcanbook.me) is changing their pricing next
> summer. I noticed there is a large number of scheduling plugins for
> Wordpress and wondered if anyone out there is using one for scheduling
> librarian research consultations. Need to display open slots, ideally
> populated from separate Google calendars, generate emails to librarian and
> students, once slot is booked that time is no longer available, etc. etc.
> Unfortunately the free tiers of these plugins generally don’t come the
> stuff you’d actually need to test, so it’s hard to know how good they are.
>
> Other low-cost solutions also welcome; I know everyone is using LibCal but
> I can’t stomach nearly doubling our Springshare invoice for a single
> function that up till now has been free… (we don’t need an events calendar,
> just appointment scheduling).
>
> --
> Jeff Karlsen
> Librarian & Library Department Chair
> Sacramento City College
> 916-558-2583
> www.scc.losrios.edu/library<http://www.scc.losrios.edu/library>
>
>