error on displayng next opening

Hi Maarten really love the idea of your plugin.
I get some errors on a dev local site
1) if I activate the “Opening/closing soon warning option” this give the following response. int 60 and after the correct message.
2) Changing the opening hour some time did not update the messagge.

I really love if you can activate in the next version some upgrades like:
– Have the ability to set opening hours also by 15 minutes
– Have the ability to set holiday period
– have the ability to set the Opening/closing soon warning option time
I will pay for it
Fabrizio