It literally says the manhwa is in 2036 post wwIII?
june 13 2014 is ban
june 1 2017 is shinwi
september 22 1999 is ray
ban bein that many years older than shinwi makes sense since it was established he is several years older in the beginnin which is why shinwi calls him hyung and they even had that flashback of them bein kids
And ray findin a kid while he himself is 15 doesnt make sense so i interpret june 13 bein the day he was found not the 2014 im sure it was mentioned in the story how long ray and ban known and lived with each other so ill have to go back and reread

ray bein 15 years older than ban and hes 37 like leave smb in their 20s alone tryin to take his youth you useless yuck
a lot of yall takin the ages of when they were born to heart like are we in the year 2036 rn theyre older than a lot of us