Refactoring

lib/services/tools.dart

@@ -0,0 +1,12 @@
+import 'package:resume/constants.dart' show months;
+
+class Tools {
+  /// builds timespan-String out of two date-Strings.
+  /// Date has to be formatted as yyyy-MM
+  static buildTimeString(String startDate, String endDate) {
+    if (startDate.isEmpty || endDate.isEmpty) return '';
+    final firstDate = DateTime.parse('$startDate-01');
+    final secondDate = DateTime.parse('$endDate-01');
+    return '${months[firstDate.month - 1]} ${firstDate.year} - ${months[secondDate.month - 1]} ${secondDate.year}';
+  }
+}