Php timer-scheduled task sleep is not executed after the page is refreshed

It is also a wonderful demand for customers. we need to create a scheduled task in php and execute it in N days. the method I found on the internet is to use the while loop, which uses sleep () control the task start time, but the problem is that the page cannot jump before the start time. if I write the jump to sleep, sleep is not executed. In fact, the biggest headache is that when sleep is executed, the customer cannot do anything else, and the customer needs a long scheduled time, almost four days, so I would like to ask if there is any other way for the php timer sleepphp

It is also a wonderful demand for customers. we need to create a scheduled task in php and execute it in N days. the method I found on the internet is to use the while loop, which uses sleep () control the task start time, but the problem is that the page cannot jump before the start time. if I write the jump to sleep (), the sleep will not be executed.
In fact, the biggest headache is that the customer cannot do other things during sleep execution, and the customer needs a long scheduled time, which is about four days. Therefore, I would like to ask if there is any other way.