Assalamu alaikum sis Happy Ramadan Mubarak

Narrated Ibn Umar: I heard Allah's apostle saying"when u c the crescent(of d month of Ramadan)start fasting,and when u see crescen(of d month of shawwal)stop fasting.and if d sky s overcast&(u can't c it) then regard d crescent of Ramadan (as of 30 days)