Today I am sharing my of the prompt 'oldest untried' a decade on from the original which you can see here. Oldest current untried was Nails Inc One Tough Cookie which was from 2021, although I didn't get it until earlier this year.
My oldest untried polish is from around the beginning of December last year.
Dystopia Nail Polish - Couldn't Miss This One This Year
The reason why it is still untried is because it is a photo-chromatic polish, and while I have technically worn it, it was so overcast that I wasn't able to see any colour shift. It will stay in my untried pile until the sun finally returns to the North of England!