time travel

i was new to the game when the camping event was on and i didn’t realise it was a limited thing, i’ve used 3d print for everything except the tent kits. i really want to make a campsite but i’m not quite sure how the time travel works in this game. i did it years ago for turnips in animal crossing, do you just change the date on ur switch to the date of the event? will i still have all the same buildings and items i have now? also if anyone can remember what date it was and if it was red crystals (i think it was) that you had to trade for the camping stuff