Making this as I replied to an old thread on the topic weeks ago but never got any reply.
We have been using the product since the start of 2017 and on the old booking system (where you had far more options with layout and look of the calendars) it always used to show booked slots with a line through and coloured to whatever you had set your ‘BUSY’ time too (mostly greyed out). This always seemed to remain for us, even up until last year - however now it ONLY shows the spaces we have available.
This may be more convenient for lots of users, but some like ourselves rely on the social proof of others having booked spaces at our events (or when others can see the full range of times that were originally available for the event) and it has a massive effect on bookings. So, for example, if you can only see 5 spaces available at the event, you are not sure if there are lots of other people already booked in or if there were ONLY 5 spaces ever available at the event and no-one is booked in. This really does have a massive impact for us.
The option for us to be able to manually turn this on in settings needs be introduced if you are going to default it gone. Completely get that it is unneeded for lots of users but it was something that has always been a part of the product for us for the last 7 years and it is now impacting our bookings considerably.
We ran our last event in October and it was still showing busy slots up until then.