CalSO vs. Freshman Orientation

My international friend and I both got accepted to UC Berkeley and we were wondering if there was any difference between Freshman Orientation and CalSO. Everyone is telling me that CalSO is very important for freshman for getting the good classes but the last CalSO is in 18-19 June for the College of Chemistry, while the Freshman Orientation is in 17 August. Since my friend isn’t on College Confidential, my question is, is it worth for him to come 2 months earlier just for CalSO?

http://calso.berkeley.edu/c-fees.html#cant for those who cannot attend CalSO.

This could mean being last to register, so s/he may have to take classes at less desired times like 8am.

College of Chemistry sample schedules are shown here:

http://chemistry.berkeley.edu/student_info/undergrad_info/degree_programs/cheme_major/index.php
http://chemistry.berkeley.edu/student_info/undergrad_info/degree_programs/chem_major/index.php

Of course, some students may start in a more advanced math course than Math 1A; this may also enable taking Physics 7A in the first semester.