add previous functionality

HanyadikHetVan/DTO/HanyadikHetVanDTO.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace HanyadikHetVan.DTO
+{
+    public class HanyadikHetVanDTO
+    {
+        private readonly DateTime startdate;
+
+        public HanyadikHetVanDTO(string startdate)
+        {
+            this.startdate = DateTime.Parse(startdate);
+        }
+
+        public int HanyadikHet => (DateTime.Now - startdate).Days / 7;
+    }
+}