Dear Nikola,  I tried to reply on my previous post but could not as I am not a member her. I also tried to register but never received an email. However, saying that. I posted a week ago asking about changing the css code in a way that the dates with no slots will be shown in a different colour (let's say Red). I tried changing the css codes and played with all the possible lines in the calendar but could not manage to find the solution.  I am using the older version of the plugin and the web designers managed to customise it a bit for me in a way that it is now.  Could you please help me on finding the right css code and tell me where I can implement it? I am also willing to pay and support this amazing plugin.  I have tried the new version of the plugin as well on my local host but it does not have the category option unfortunately and I could not customise it in the same way as it looks right now. I desperately need to your help on this please.  Many thanks, Rez (Romeo) https://mypureaesthetics.com/online-booking/