How can I find unoccupied time in the lunch-time gap?

Question

PHP

Hello.
The database stores working time and lunch in JSON in one column
I have a master who has a working time period and lunch or several breaks
There are different services, for example 1 hour 15 minutes, 30 minutes, etc.
Services are stored in the database by 1 line in datetime format The
question is how to check the time interval in PHP in order to write a new service, taking into account not to overlap with another.
The implementation is in PHP, since the system can no longer be redone

Answer 1

Already answered a similar question: How to check booked dates in a range of numbers?
You can take the validation class from there. You will only need to add the time to the constructor.

Answer 2

I had a similar project with table reservations in a restaurant, but the average load at a certain time was also calculated there, and so on.
Briefly:
1) Use intervals of time. If the service is 15 minutes, then write down the type of service, start time and end time. For subsequent calculations, this will be a plus.
2) Next, check the interval, whether it is included in any of the existing ones.