The federal regulations specify that the triennial status report is due by February, every three years, starting from 1985. Based on this information, one can caculate in which years future triennial status reports will be due: 2015, 2018, 2021, and so on.
A report that is filed during the month of February in the year in which reporting is due, and which is filed for the current reporting cycle, is considered to be filed timely. CBP offices will begin accepting the status report and the corresponding fee on the first day of January of the reporting year. Filing for year 2015, for example, can therefore be made between January 1, 2015 and February 28, 2015.