Allow users to add their friends or families birthdays

Play music in the background of a countdown

July 4th

At the time of a person's celebration congratualte them on their celebaration

Presidential Inauguration 2020

how many days till your period

Mobile World Congress; 27 Feb-2 March, Barcelona
https://www.mobileworldcongress.com/

A day where sisters all get together and go shopping, exchange gifts and have a meal together while sharing childhood stories about the times they were kids and take photos of that day

I think for the the birthday count down me personally i think there should be a place where you could put the time you were born so you could have the exact countdown. That would be really nice.

Release dates for Video games (Console, PS2, PS3, PS4, XBox, Nintendo, 3DS, Wii, Xbox One, Xbox 360, PC, Mac, Steam, Vita)

Go to school or work dressed as the craziest thing you can be. Don't let the government tear down our fun!

Baseball

Certain events happen at different times depending on which side of the world you're on (spring, summer, winter, autumn/fall etc.)

days until summer break

For Apple

A secular festival observed by many African Americans from 26 December to 1 January as a celebration of their cultural heritage and traditional values.