Season Guide

Explanation of all seasons:

Christmas:
When Christmas starts, you will unlock an upgrade called "A festive hat" which costs 25 cookies, buying this upgrade will unlock Santa in the lower left corner and a random Santa's gift, a Christmas themed upgrade. He can be evolved by using cookies, unlocking the rest of Santa's gifts.
Christmas will also allow reindeer to spawn. They spawn from the left side of the screen and travel to the right. Clicking them will give one minute of your cps, and have a chance at unlocking a reindeer cookie.

achievements:
Coming to Town: Reach Santa's 7th form.
All hail Santa: Reach Santa's final form.
Let it snow: Unlock all 7 reindeer cookies. (Makes reindeer cookies easier)
Oh deer: Pop one reindeer
Sleigh of Hand: Pop 50 reindeer
Reindeer sleigher: Pop 200 reindeer
Eldeer: Pop a reindeer during Elder Frenzy


Halloween:
Halloween makes wrinklers have a chance to drop a halloween cookie on pop.

achievements:
Spooky cookies: Unlock all 7 halloween cookies. (Makes halloween cookies easier)


Valentine's:
Having Valentine's active makes heart biscuits be unlocked in the shop, each progressively more expensive than the last.

achievements:
Lovely cookies: Buy all 7 heart biscuits.


Business Day:
Business Day reskins all buildings to be more business-like, and adds 2 joke stats to the stats menu. It also adds a golden cookie effect, which makes buildings 5% cheaper for 8 seconds.

achievements: none


Easter:
Easter makes wrinklers and golden cookies have a chance to drop an egg, which can give either just a cps boost, or some special boost.

achievements:
The hunt is on: Unlock 1 egg
Egging on: Unlock 7 eggs
Mass Easteria: Unlock 14 eggs
Hide & seek champion: Unlock all 20 eggs (Makes eggs easier)



Strategy with the season switcher:

You will almost always want to start with Christmas, as Santa is a huge buff, makes the other seasons a bit easier, and does not benefit from the grandmapocalypse having started. If you are still making fast progress in the game, you will want to switch off of christmas instantly after unlocking Santa, but later on you may also want to get the reindeer cookies in this step as to not use an unneeded season switch.

After this, you will want to go with Valentine's, as it is a fast and easy buff to cps. If you cannot easily afford all of the heart cookies, just move on from this after buying the ones you can.

Next, you will want to do Easter and Halloween. There are a number of different ways to do this, depending on your stage of the game:
Way 1: Fast progress being made
Just start Easter and you will get some eggs before ascending.
Way 2: Casual
Start Easter, get all the eggs, then go to Halloween and get all the halloween cookies
Way 3: Micromanaging
Start Halloween, but anytime you get a cookie storm quickly switch to Easter and click the cookie storm cookies to get eggs.
Way 4: Dragon Orbs
This is a strategy which gives the eggs very quickly, but is very involved. You will want to not buy Get Lucky, then in the third stage of the grandmapocalypse try to activate dragon orbs anytime you don't have a buff. After doing this, buy Get Lucky, switch to Halloween and get the halloween cookies normally.

After this, if you didn't get the reindeer cookies when in Christmas, you will want to get those.

After having finished every season, you will usually want to stay in Halloween, because it gives a golden cookie frequency bonus if you have the heavenly upgrade or Selebrak and does not add an useless effect. Easter and Valentine's are also valid options, but they affect fthof results which may mess up scrying.
Business day gives a larger golden cookie frequency bonus both from the heavenly upgrade and Selebrak, but because of Everything Must Go it is not worth to use it unless: You only want to get 1 natural effect in a row, You are farming golden cookie clicks, or you have Selebrak in ruby or above. It can also mess up Godzamok usage if you are not accustomed to it.
Christmas is not good after you have finished all the seasons. It does not give a golden cookie frequency boost, and reindeer are heavily overshadowed in combos. The only exception would be when you have not gotten any of the seasonal heavenly upgrades, but you would usually not be able to finish them because progress is so fast at that point.



Extra tips:
Chocolate Egg should not be bought the instant you get it, but you should rather wait until the end of the ascension, sell all your buildings, and get it.
All of the seasonal drops are considered random drops, which means that Mind over Matter and such will work on them. The chances are also organized weirdly, so additional random drop rate buffs are much more effective the less of them you already have.
Seasons can also be activated through actually waiting for the time of year for them to arrive (Business Day is for April Fools)

If you want to give feedback or complain that guide is bad you can find me on discord at Lookas123#8194.