The TZ function is not the same as the TIMEZONE function

lib/src/sparql/algebra.rs

@@ -458,6 +458,7 @@ pub enum Expression {
     MinutesFunctionCall(Box<Expression>),
     SecondsFunctionCall(Box<Expression>),
     TimezoneFunctionCall(Box<Expression>),
+    TzFunctionCall(Box<Expression>),
     NowFunctionCall(),
     UUIDFunctionCall(),
     StrUUIDFunctionCall(),
@@ -568,6 +569,7 @@ impl fmt::Display for Expression {
             Expression::MinutesFunctionCall(e) => write!(f, "MINUTES({})", e),
             Expression::SecondsFunctionCall(e) => write!(f, "SECONDS({})", e),
             Expression::TimezoneFunctionCall(e) => write!(f, "TIMEZONE({})", e),
+            Expression::TzFunctionCall(e) => write!(f, "TZ({})", e),
             Expression::NowFunctionCall() => write!(f, "NOW()"),
             Expression::UUIDFunctionCall() => write!(f, "UUID()"),
             Expression::StrUUIDFunctionCall() => write!(f, "STRUUID()"),
@@ -818,6 +820,7 @@ impl<'a> fmt::Display for SparqlExpression<'a> {
             Expression::MinutesFunctionCall(e) => write!(f, "MINUTES({})", SparqlExpression(&*e)),
             Expression::SecondsFunctionCall(e) => write!(f, "SECONDS({})", SparqlExpression(&*e)),
             Expression::TimezoneFunctionCall(e) => write!(f, "TIMEZONE({})", SparqlExpression(&*e)),
+            Expression::TzFunctionCall(e) => write!(f, "TZ({})", SparqlExpression(&*e)),
             Expression::NowFunctionCall() => write!(f, "NOW()"),
             Expression::UUIDFunctionCall() => write!(f, "UUID()"),
             Expression::StrUUIDFunctionCall() => write!(f, "STRUUID()"),

lib/src/sparql/sparql_grammar.rustpeg

@@ -786,7 +786,8 @@ BuiltInCall -> Expression =
 	"HOURS"i _ '(' _ e:Expression _ ')' { Expression::HoursFunctionCall(Box::new(e)) } /
 	"MINUTES"i _ '(' _ e:Expression _ ')' { Expression::MinutesFunctionCall(Box::new(e)) } /
 	"SECONDS"i _ '(' _ e:Expression _ ')' { Expression::SecondsFunctionCall(Box::new(e)) } /
-    ("TIMEZONE"i / "TZ"i) _ '(' _ e:Expression _ ')' { Expression::TimezoneFunctionCall(Box::new(e)) } /
+    "TIMEZONE"i _ '(' _ e:Expression _ ')' { Expression::TimezoneFunctionCall(Box::new(e)) } /
+    "TZ"i _ '(' _ e:Expression _ ')' { Expression::TzFunctionCall(Box::new(e)) } /
 	"NOW"i _ NIL { Expression::NowFunctionCall() } /
 	"UUID"i _ NIL { Expression::UUIDFunctionCall() }/
 	"STRUUID"i _ NIL { Expression::StrUUIDFunctionCall() } /