11th and 10th-grade students (and sometimes 9th) often take PSAT in October. Make sure your school registers them by: this Wednesday, September 15th

https://collegereadiness.collegeboard.org/psat-nmsqt-psat-10/k12-educators/psat-nmsqt-dates

The Fall ACT and SAT are often taken by seniors who need one or two more cracks at it. 

October ACT registration date is: September 17, 2021

October ACT test date: October 23, 2021

December ACT registration date: November 5, 2021

December ACT test date: December 11, 2021

November SAT registration date: October 8, 2021

November SAT test date: November 6, 2021

December SAT registration date: November 4, 2021

December SAT test date: December 4, 2021

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