Fall
Remembrance Day (Beginning of fall) - A day to remember the dead. I'm not sure how I'll implement this yet until I see what kind of options we have.
Spooky day (Middle Autumn - Halloween) A day sims will dress in costumes and decorate their house with spooky decor. Invite family and friends over for a scary party.
Turkey Day (Late Autumn - Thanksgiving) Will invite family over to eat all kinds of good food (lots of turkey) and watch the sports channel.
Winter
Winter Fest (Early Winter - Christmas) Leading up to this day they will decorate the tree and leave cookies out for Santa. Will open gifts with family and spend the day doing outdoor activities with their family.
New Years (Middle of Winter) Will throw a party and celebrate a new year with family and friends while watching the countdown.
Creation Day (Sime 1 came out- End of Winter) Kind of like a big birthday party for all sims without gifts. They spend time with family and friends and eat cake while decorating the house in balloons and streamers. Lots of different desserts to choose from too!
Spring
Love Day (Early Spring- Valentines Day) Sims will surprise their loves with flowers and gifts and take them out for a nice dinner and maybe end with woohoo.
Egg Day (Middle Spring- Easter) Sim children will anxiously await the Bunny to come and give them gifts and they will search for eggs in the yard. (not sure if we have a bunny npc or not or egg hunts so this may change) Maybe decorate eggs and eat eggs.
Lucky/Green Day (End of Spring - St. Patrick's day for Sims) Sims will dress in green and wear funny outfits and adults will drink and be silly.
Summer
Prank Day (Early Summer - April Fools) All sims will have fun pranking each other and doing some sort of mischief.
Parent's day (Middle Summer- Mother and Father's day together) A day when sims will honor their parents by inviting them over or to the park to cook out (usually hot dogs and hamburgers). They may also give their parents gifts.
Freezer Bunny Day (Late Summer- replacement for 4th of July) They will eat ice cream, play in the pool, cookout, and go see the fireworks. It's a special celebration for all sims.