diff --git a/src/core/expression/qgsexpressionfunction.cpp b/src/core/expression/qgsexpressionfunction.cpp
index 81cd40df84b0..1344aa3777f9 100644
--- a/src/core/expression/qgsexpressionfunction.cpp
+++ b/src/core/expression/qgsexpressionfunction.cpp
@@ -5807,10 +5807,14 @@ static QVariant fcnFormatNumber( const QVariantList &values, const QgsExpression
 
 static QVariant fcnFormatDate( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )
 {
-  const QDateTime datetime = QgsExpressionUtils::getDateTimeValue( values.at( 0 ), parent );
+  QDateTime datetime = QgsExpressionUtils::getDateTimeValue( values.at( 0 ), parent );
   const QString format = QgsExpressionUtils::getStringValue( values.at( 1 ), parent );
   const QString language = QgsExpressionUtils::getStringValue( values.at( 2 ), parent );
 
+  // Convert to UTC if the format string includes a Z, as QLocale::toString() doesn't do it
+  if ( format.indexOf( "Z" ) > 0 )
+    datetime = datetime.toUTC();
+
   QLocale locale = !language.isEmpty() ? QLocale( language ) : QLocale();
   return locale.toString( datetime, format );
 }
diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
index 50b3a637279e..2606b68b1e17 100644
--- a/tests/src/core/testqgsexpression.cpp
+++ b/tests/src/core/testqgsexpression.cpp
@@ -1875,6 +1875,7 @@ class TestQgsExpression: public QObject
       QTest::newRow( "time from format and language" ) << "to_time('12:34:56','HH:mm:ss','fr')" << false << QVariant( QTime( 12, 34, 56 ) );
       QTest::newRow( "formatted string from date" ) << "format_date('2019-06-29','MMMM d, yyyy')" << false << QVariant( QString( "June 29, 2019" ) );
       QTest::newRow( "formatted string from date with language" ) << "format_date('2019-06-29','d MMMM yyyy','fr')" << false << QVariant( QString( "29 juin 2019" ) );
+      QTest::newRow( "formatted string with Z" ) << "format_date(to_datetime('2019-06-29T13:34:56+01:00'),'yyyy-MM-ddTHH:mm:ssZ')" << false << QVariant( QString( "2019-06-29T12:34:56Z" ) );
 
       // Color functions
       QTest::newRow( "ramp color" ) << "ramp_color('Spectral',0.3)" << false << QVariant( "253,190,116,255" );