I need a simple calendar function to run in excel (any spreadsheet) that inputs

first shipdate
number of semesters in a student's program
number of months given to complete each semester
lead time in days needed to get a package of materials to a student

outputs a list of dates when we should be sending packages of materials to a student

it would be helpful to have a feature where, if one of the dates in the output list is changed manually, the subsequent dates recalculate