Are we obligated to go to confession once per year (regardless of circumstances, and if so when)?
Can. 989 After having reached the age of discretion, each member of the faithful is obliged to confess faithfully his or her grave sins at least once a year.
Only one who is conscious of a grave sin is required to confess. This confession is to be made at least once per year. There is no stipulation as to when the confession is to take place. However it would not be wise to go long periods of time conscious of a grave sin.
Many may be familiar with the concept of “Easter Duty” under which Catholics would go to confession and receive the Eucharist during the Easter Season. Canon Law still requires us to receive communion at least once during the Easter Season (canon 920) so many people still hold to confession and communion once a year during that time.