Thank you,
I have more than 600 courses
by default, this option "Calculate the end date from the number of sections" is enabled, and courses had only 5 weeks
after 5 weeks, the courses disappeared from the courses lists (all courses are still active and students can access them using their
dashboard)
but it is confusing for many of them and I received many questions about why their courses "disappear" from the list
Moodle does not support changing the courses settings after creating them in bulk
the number of courses is really large to change it one by one
so I am trying to change this option using DB