We are experiencing timezone-related issues where incorrect and non-existent time slots appear inconsistently for certain clients. The issue is highly unpredictable, as:

• Some clients see random, incorrect time slots that do not belong to any employees or match the studio’s schedule.
• Other clients see the correct time slots.
• Some days, the schedule appears correctly, but on other days, it displays incorrect time slots.
• The issue happens differently for different users, including myself.

• WordPress Timezone: UTC +6 (correct for our studio).
• "Use Clients' Timezone" Setting: Disabled.
• Service Scheduling:
  • Services start 10 minutes past the hour and last 50 minutes (e.g., 6:10 AM – 7:00 AM).
  • Post-buffer time: 10 minutes, ensuring that the next available time slot always follows the same pattern (7:10 AM – 8:00 AM, 8:10 AM – 9:00 AM, etc.).

• Some days, the time slots display correctly. Other days, they don’t.
• Different clients see different incorrect time slots at random.
• The incorrect slots do not follow any timezone logic, nor do they belong to any employee or service.
• See attached images for reference on incorrect slot appearances.
  
  
  This is urgent as our launch is this Monday and incorrect time slots could cause booking confusion for our clients.
   Thank you in advance for your assistance!

You can see in this video, that for a specific service, in which only one employee is assigned to, despite having the exact same schedules for Monday and Tuesday (Lunes and Martes), it doesn't make sense of what's being displayed on the front end for the user panel as for both days, on two different weeks, the schedules are different.

In the first instance, on the first week, on Monday, the schedule from 8:10pm is missing.
On the consequent week, on Monday, the schedule now displays the 8:10pm timeslot.

Why?

On tuesday, it makes even less sense, why despite having the exact same schedule for both days, on the first week tuesday why does 10:10 - 11:00 am even exist, if it's out of range for that day.

This was just a simplified demo, but imagine this happening to exactly each one of my schedules.

Please help, this is super important

I had read that article before while trying to solve this issue, however, I didn't quite understand what should I do?
Should I keep it at UTC or should I set to my closest city?

I did that, the UTC and my city timezone are the same, now I've tried with both options, but both show the same problem; inexistant timeslots appear for some days. 

Time Zone Adjustments:

• Tested UTC-6 and America/Mexico_City in WordPress settings.
• Also tested switching between UTC and city-based time zones.
• No change—incorrect time slots still appear inconsistently.

Cache Clearing & Refreshing:

• Flushed WordPress cache, Amelia cache, and transients.
• Resaved all settings in Amelia and WordPress.
• Issue persists.

Service & Employee Configuration:

• Services have 50-minute duration + 10-minute buffer and start 10 minutes past the hour.
• Deleted and recreated employee schedules to force recalculation.
• Still experiencing random missing or extra slots.
  
  
  
  I really hope this isn't some bug with time calculation from Amelia, as I really need this buffer time settings

Any luck with this? Please, this is my priority

Full time slots do disappear, that has not been a problem, the only persistent problem is the out of range random time slots. 

For example in your screenshot; February 20th (or any day) shouldn’t have any time slot from 9:00 - 9:50 or similar. These time slots are not considering the buffer time and are causing a management hell on my side as I have to manually re do the appointments for people in the 9:10-10:00 and 9:00 - 9:50 range.

Is this a known bug? What else can I do? I don’t want my management system to be more of a hassle. :(

I've been trying with a million different settings and there's no progress at all, this is already damaging the business workflow and confusing clients.
I just want to know if there's no fix, I'd rather ask for a refund.

Hello Stefan, thanks for your response.

In the meantime while I received a response for this matter, I actually figured a way to fix this bug on my own.
And as much as I appreciate your answer, you checked the website when I've already solved the issue.

This is a bug.

For whoever lurking that may be getting random/wrong timeslots, here's what I did:



Create a blank, new employee; this seemed to have forced the plug-in to recalculate the time-slots correctly.

And if that doesn't solve it.

Delete and create your employee profiles again.