Challenge with time slots (duration of service, time picker)

Hello, I do have the following challenge with the splendid Salon booking plugin: The shortest duration of my services is 20 minutes. To start a shift it seems I can only choose between 0, 20 and 40 minutes. Now I would like to start a shift at 30 minutes after the hour. I didn’t find a way to achieve this.

Is there a setting that I haven’t seen, or a workaround for this problem?

Thanks so much for an answer and keep on with your great work on this plugin!

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