SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function age (children 1) ExpressionList (children 3) Literal \'second\' Function toDateTime (children 1) ExpressionList (children 2) Literal \'2017-12-31 00:00:00\' Literal \'UTC\' Function toDateTime (children 1) ExpressionList (children 2) Literal \'2018-01-01 00:00:00\' Literal \'UTC\'