The race time limit is in the sailing instructions. If at least one boat sails the course within it, the race counts and every boat that finishes is scored by finishing place, even if they finish after the limit, unless the race is abandoned. Many events add a finishing window (scored TLE) that changes this rule for later boats; see Appendix A.
RRS 2025–2028 · Part 3
35 Race Time Limit and Scores
If one boat sails the course within the time limit, every boat that finishes is scored; otherwise the race is abandoned.