| 2012 | ||
| Jun 13 | Wed | Classes Begin / Opening Exercises / Orientation for Freshmen |
| Jun 23 | Sat | CLSU Science High School PTA First General Assembly Meeting |
| Jul 13 | Fri | Acquaintance and Induction Party |
| Jul 20-21 | Fri-Sat | Grubstreet (Campus Journalism Seminar Workshop |
| Jul27 | Fri | Tree Planting |
| Aug 8,9,10 | W,Th,F | First Periodical Examination |
| Aug | Open Date | University Intramurals |
| Aug 20 | Mon | Eid-ul Fitr (Legal Holiday |
| Aug 21 | Tue | Ninoy Aquino Day |
| Aug 22 | Wed | Last Day of submission of First Grading Grades |
| Aug 29 | Wed | National Career Assessment Examination(NCAE) |
| Aug 30 | Fri | Buwan ng Wika / Tagisan ng Talento |
| Sep 10 | Fri | Distribution of Report Cards |
| Sep 17 | Mon | Math Day |
| Oct 10,11,12 | W,Th,F | 2nd Periodical Examination |
| Oct 15 | Mon | Teachers' Day |
| Oct 22 | Mon | Last Day for submission of 2nd Grading Grades |
| Oct26-Nov4 | Semestral Break | |
| Nov 5 | Mon | Classes Resume |
| Nov 8-9 | Mon | Field Trip |
| Nov 15/16 | Mon | Distribution of Report Card |
| Nov 22 | Thu | University Baccalaureate and Tea Party |
| Nov 23 | Thu | University Mid-Year Commencement Exercises |
| Nov 30 | Tue | Bonifacio Day (Legal Holiday) |
| Dec 5,6,7 | W,Th,F | Third Periodical Examination |
| Dec 9 | Sat | CLSU Science High School PTA Second General Assembly Meeting |
| Dec -- | Th F | Christmas Celebration / Lantern Parade |
| Dec 17 | Mon | Start of Christmas Break |
| 2013 | ||
| Jan 3 | Th | Classes Resume |
| Jan 10-11 | T-W | USHS Sports Fest |
| Jan 14 | Fri | Last Day for submission of 3rd Grading Grades |
| Jan 23 | Wed | Last Day for filing of USHS Entrance Examination Application |
| Jan 26 | Sat | USHS Entrance Examination |
| Jan 28 | Fri | Distribution of Report Cards |
| Feb 8 | Fri | Juniors-Seniors Promenade |
| Feb 18-21 | M-F | USHS Science Fair and Exhibits |
| Feb 25 | Mon | EDSA People Power I Anniversary |
| Mar 6 | Wed | National Achievement Test |
| Mar 7,8,11 | Th,F,M | 4th Periodical Examination |
| Mar 18 | M | Last day of submission of Fourth Grading Grades |
| Mar 21 | Th | USHS Academic Council |
| Apr 3 | Wed | AM - USHS Baccalaureate Service PM - USHS Tea Party |
| Apr 4 | Thu | AM - USHS Achievement Day / Promotional, Recognition and Commencement Exercises PM - Distribution of Report Card |
| Apr -- | --- | USHS Enrolment for SY 2013-2014 |