weather prognostication day in Belgium. More Feast day of St Isaiah Eighth century BCE Old Testament prophet and martyr, killed at the order of King Manasseh of Juda. Isaiah ( Hebrew ישעיהו Yəša'ăyāhû, Yesha'ayahu , Y'sha'ayahu , Yeshayahu , Y'shayahu 'Salvation of/is the LORD ') was the son of Amoz, married