given ($year_anchor_day){
    when(0){@anchorday_week = qw(tuesday wednesday thursday friday saturday
    sunday monday );}
    when(1){@anchorday_week = qw(wednesday thursday friday saturday sunday
    monday tuesday);}
    when(2){@anchorday_week=qw(thursday friday saturday sunday monday tuesday
    wednesday);}
    when(3){@anchorday_week=qw(friday saturday sunday monday tuesday wednesday
    thursday);}
    when(4){@anchorday_week=qw(saturday sunday monday tuesday wednesday
    thursday friday);}
    when(5){@anchorday_week=qw(sunday sunday monday tuesday wednesday friday
    saturday);}
    when(6){@anchorday_week = qw(monday tuesday wednesday thursday friday
    saturday sunday);}
}