@ShearBlessed, this sounds really weird.
I know in some cases when you're going to book an appointment the page will recognize the time zone of your device your using and ask your customer for a preference. This could cause some of your customers to receive their notifications in a different time zone.
I recommend taking a look at the profiles for your clients and seeing which timezone they have selected. From the profile page you can manually adjust their time zone to CST.
If it's still giving you trouble please let me know!
