SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function dateDiff (children 1) ExpressionList (children 3) Literal \'hours\' Function toDateTime (children 1) ExpressionList (children 2) Literal \'2017-12-31\' Literal \'UTC\' Function toDateTime (children 1) ExpressionList (children 2) Literal \'2016-01-01\' Literal \'UTC\'