Tips for invitation timing

Anniversary party: 3 to 6 weeks
Baby shower: 4 to 5 weeks
Bar or Bat Mitzvah: 1 month
Birthday party: 3 to 4 weeks
Bridal shower: 4 to 5 weeks
Bon Voyage party: Last minute to 3 weeks
Casual party: Same day to 2 weeks
Charity Ball: 6 weeks to 3 months
Christmas party: 1 month
Cocktail party: 1 to 4 weeks
Formal dinner: 3 to 6 weeks
Graduation party: 3 weeks
Housewarming party: A few days to 3 weeks
Informal dinner: A few days to 3 weeks
Lunch or Tea: A few days to 2 weeks
Shower
Thanksgiving dinner: 2 weeks to 2 months