diff --git a/cron-sample.sh b/cron-sample.sh
index 0e5a804..b38db5c 100644
--- a/cron-sample.sh
+++ b/cron-sample.sh
@@ -8,8 +8,10 @@
 # 4- instance domain (https:// is automatically added)
 # 5- max age (in days)
 # 6- footer tags to add (optional)
+# 7- delay (optional)
+# 8- visibility unlisted (if 0 or unset visibility is public, if 1 visibility is unlisted)
 
 python3 tootbot.py geonym_fr geonym@amicale.net **password** test.amicale.net
 python3 tootbot.py cq94 cquest@amicale.net **password** test.amicale.net
 
-python3 tootbot.py https://www.data.gouv.fr/fr/datasets/recent.atom cquest+opendata@amicale.net **password** amicale.net 2 "#dataset #opendata #datagouvfr"
+python3 tootbot.py https://www.data.gouv.fr/fr/datasets/recent.atom cquest+opendata@amicale.net **password** amicale.net 2 "#dataset #opendata #datagouvfr" 0 1
diff --git a/tootbot.py b/tootbot.py
index a91e021..45d4059 100755
--- a/tootbot.py
+++ b/tootbot.py
@@ -37,7 +37,7 @@ def unredir(redir):
 
 
 if len(sys.argv) < 4:
-    print("Usage: python3 tootbot.py twitter_account mastodon_login mastodon_passwd mastodon_instance [max_days [footer_tags [delay]]]")  # noqa
+    print("Usage: python3 tootbot.py twitter_account mastodon_login mastodon_passwd mastodon_instance [max_days [footer_tags [delay [unlisted]]]]")  # noqa
     sys.exit(1)
 
 if len(sys.argv) > 4:
@@ -60,6 +60,11 @@ def unredir(redir):
 else:
     delay = 0
 
+if len(sys.argv) > 8 and (int(sys.argv[8]) == 1):
+    mastodon_visibility = "unlisted"
+else:
+    mastodon_visibility = "public"
+
 source = sys.argv[1]
 mastodon = sys.argv[2]
 passwd = sys.argv[3]
@@ -126,10 +131,17 @@ def unredir(redir):
         db.execute('SELECT * FROM tweets WHERE tweet = ? AND twitter = ?  and mastodon = ? and instance = ?', (id, source, mastodon, instance))  # noqa
         last = db.fetchone()
         dt = t.published_parsed
-        age = datetime.now()-datetime(dt.tm_year, dt.tm_mon, dt.tm_mday,
+        # if the date of a feed is invalid, the parser might return a NoneType
+        if dt is None:
+            print("Couldn't parse feed date, ignoring date...")
+            process = last is None
+        else:
+            age = datetime.now()-datetime(dt.tm_year, dt.tm_mon, dt.tm_mday,
                                     dt.tm_hour, dt.tm_min, dt.tm_sec)
-        # process only unprocessed tweets less than 1 day old, after delay
-        if last is None and age < timedelta(days=days) and age > timedelta(days=delay):
+            # process only unprocessed tweets less than 1 day old, after delay
+            process = last is None and age < timedelta(days=days) and age > timedelta(days=delay)
+
+        if process:
             c = t.title
             if twitter and t.author.lower() != ('(@%s)' % twitter).lower():
                 c = ("RT https://twitter.com/%s\n" % t.author[2:-1]) + c
@@ -196,7 +208,7 @@ def unredir(redir):
                                                 in_reply_to_id=None,
                                                 media_ids=toot_media,
                                                 sensitive=False,
-                                                visibility='public',
+                                                visibility=mastodon_visibility,
                                                 spoiler_text=None)
                 if "id" in toot:
                     db.execute("INSERT INTO tweets VALUES ( ? , ? , ? , ? , ? )",