diff --git i/src/backend/parser/gram.y w/src/backend/parser/gram.y
index 8fc79b6..75a27ff 100644
--- i/src/backend/parser/gram.y
+++ w/src/backend/parser/gram.y
@@ -9452,6 +9452,19 @@ b_expr:		c_expr
 				{ $$ = $1; }
 			| b_expr TYPECAST Typename
 				{ $$ = makeTypeCast($1, $3, @2); }
+			| b_expr AT TIME ZONE b_expr
+				{
+					FuncCall *n = makeNode(FuncCall);
+					n->funcname = SystemFuncName("timezone");
+					n->args = list_make2($5, $1);
+					n->agg_order = NIL;
+					n->agg_star = FALSE;
+					n->agg_distinct = FALSE;
+					n->func_variadic = FALSE;
+					n->over = NULL;
+					n->location = @2;
+					$$ = (Node *) n;
+				}
 			| '+' b_expr					%prec UMINUS
 				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "+", NULL, $2, @1); }
 			| '-' b_expr					%prec UMINUS