Cardinal Students is the online system for registering for classes. 

To find add/drop dates for summer, go into Cardinal Students, select class search. When you select, click on the "Academic Calendar" icon and the deadlines will appear.

Additional Notes

All classes offered by Library and Information Science are "LSC" courses. Note 
"CLSC" is no longer used for courses taught at Library of Congress.

Academic Term Codes
Although it may appear that the 4-digit codes for academic semesters are random, the code actually reflects the starting date of each semester:

The last digit is the month in which each semester begins. Thus spring semesters will always end in a 1 for January, summer semesters will end in a 5 for May, and fall semesters will end in an 8 for August.

The second and third digits represent the year.

The first digit reflects the century:  1 = 21st century.

For example, the summer 2020 term  is 1205: 1=21st century, 20=the year, 5=May