diff --git a/src/calibre/ebooks/mobi/writer2/main.py b/src/calibre/ebooks/mobi/writer2/main.py
index 1819850827..881f2bd199 100644
--- a/src/calibre/ebooks/mobi/writer2/main.py
+++ b/src/calibre/ebooks/mobi/writer2/main.py
@@ -34,6 +34,8 @@
     'rights': 109,
     'type': 111,
     'source': 112,
+    'versionnumber': 114,
+    'lastupdatetime': 502,
     'title': 503,
     }
 
@@ -329,7 +331,7 @@ def generate_record0(self): #  MOBI header {{{
             if self.indexer.is_flat_periodical:
                 bt = 0x102
             elif self.indexer.is_periodical:
-                bt = 0x103
+                bt = 0x101
 
         record0.write(pack(b'>IIIII',
             0xe8, bt, 65001, uid, 6))
@@ -500,10 +502,12 @@ def build_exth(self): # EXTH Header {{{
 
         # Write cdetype
         if self.is_periodical:
+            data = b'NWPR'
+        else:
             data = b'EBOK'
-            exth.write(pack(b'>II', 501, len(data)+8))
-            exth.write(data)
-            nrecs += 1
+        exth.write(pack(b'>II', 501, len(data)+8))
+        exth.write(data)
+        nrecs += 1
 
         # Add a publication date entry
         if oeb.metadata['date']:
@@ -511,18 +515,28 @@ def build_exth(self): # EXTH Header {{{
         elif oeb.metadata['timestamp']:
             datestr = str(oeb.metadata['timestamp'][0])
 
-        if datestr is not None:
-            datestr = bytes(datestr)
-            exth.write(pack(b'>II', EXTH_CODES['pubdate'], len(datestr) + 8))
+        if datestr is None:
+            raise ValueError("missing date or timestamp")
+
+        datestr = bytes(datestr)
+        exth.write(pack(b'>II', EXTH_CODES['pubdate'], len(datestr) + 8))
+        exth.write(datestr)
+        nrecs += 1
+        if self.is_periodical:
+            exth.write(pack(b'>II', EXTH_CODES['lastupdatetime'], len(datestr) + 8))
             exth.write(datestr)
             nrecs += 1
-        else:
-            raise NotImplementedError("missing date or timestamp needed for mobi_periodical")
+            exth.write(pack(b'>III', EXTH_CODES['versionnumber'], 12, 7))
+            nrecs += 1
 
-        # Write the same creator info as kindlegen 1.2
-        for code, val in [(204, 201), (205, 1), (206, 2), (207, 33307)]:
-            exth.write(pack(b'>II', code, 12))
-            exth.write(pack(b'>I', val))
+        if self.is_periodical:
+            # Pretend to be amazon's super secret periodical generator
+            vals = {204:201, 205:2, 206:0, 207:101}
+        else:
+            # Pretend to be kindlegen 1.2
+            vals = {204:201, 205:1, 206:2, 207:33307}
+        for code, val in vals:
+            exth.write(pack(b'>III', code, 12, val))
             nrecs += 1
 
         if (oeb.metadata.cover and