SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function age (children 1) ExpressionList (children 4) Literal \'month\' Function toDateTime (children 1) ExpressionList (children 2) Literal \'2015-08-18 00:00:00\' Literal \'UTC\' Function toDate32 (children 1) ExpressionList (children 2) Literal \'2015-09-18\' Literal \'UTC\' Literal \'UTC\'