There are four contests during the regular season. The window during which the contest can be accessed on HackerRank is as follows.
Contest #1: completed
Contest #2: is available now; closes Sunday March 7 @ 11:59pm EST
Contest #3: is available now; closes Sunday April 11 @ 11:59pm EDT
Contest #4: will be available March 5, 2021; closes Sunday May 16 @ 11:59pm EDT
Based on the scores during the regular season, top students in all divisions will be invited to participate in an online Finals competition:
Invitations E-mailed: May 1, 2021*
Invitational Finals: Saturday, May 29, 2021 (Memorial Day weekend in the US)
There is a nominal per-student registration fee to participate in the Finals.
*For scores arriving after May 1st (and by May 16th), invitations to qualified students will be emailed as results are received by ACSL.