You can block the time selected on the calendar in two clicks.
To do this, you need to make a small pre-configuration.
Let's say we have such a resource:
Create a new Non-wroking hours rule with an empty schedule.
This rule should have the highest priority.
Press the Reorder button.
Drag the rule down.
Then it will overlap the rest of the rules.
You will get the configuration like this:
Now go to the order cart.
Click Block time.
Select the resource and time you want to block.
After that, you will see a drop-down list of non-working rules.
Select the rule you created and click Add period.
The selected time will disappear from the list of available slots.
If you need to block the whole day, then add a period for the whole day in the non-working rule.
The result looks like this:
If you want to unlock this time slot, simply delete the created period from the rule.