天有不测风云，人有旦夕祸福

tiān yǒu bù cè fēng yún , rén yǒu dàn xī huò fútianyoubucefengyun,renyoudanxihuofu

1. fortune as unpredictable as the weather, every day may bring fortune or calamity (idiom); sth unexpected may happen at any moment

Study it in Yanamino