If someone died with his unfulfilled fasting his next to kin should perform fast in his stead

              

                Hadith of the day 

Aisha (عائشة بنت أبي بكر‎ ) also relates that the Prophe (ﷺ) said, “ When someone dies and he has left some prescribed fasting obligations unfulfilled, his next of kin should perform the fast in his stead." 

[Al-bukhari and Muslim, Riyad Al-Sālihīn no° 1858]