We can schedule tweets using TweetDeck (Closes: #16681)

It's an official Twitter app that works with the same login, so doesn't
affect the security of our account.

wiki/src/contribute/how/documentation/release_notes.mdwn

@@ -79,14 +79,19 @@
   - Prepare a tweet with highlights:
     - Tails x.y is out: https://tails.boum.org/news/version_x.y/, bla bla bla, and more.
     - Add it as a comment to the ticket for the release notes.
-  - If we release new major features ("New features" section), consider
-    scheduling tweets in the future to let the world know about it, even
+  - If we release new major features ("New features" section),
+    schedule tweets in the future to let the world know about it, even
     months after we release them.
     - Write a Tweet, for example:
       - Did you know?
         You can xxx in Tails, since $MON (Tails $VERSION).
-      - Add the picture we had in the release notes.
       - Link to our documentation about the feature.
-    - Create a ticket to tweet about it 3 times in the following 6
-      months, for example once every 2 releases.
-    - Put this ticket on the Technical writing view in Redmine.
+      - Add a picture, for example a screenshot from the release notes
+        or the documentation.
+    - Schedule tweets using [TweetDeck](https://tweetdeck.twitter.com/).
+      - For example, tweet 3-4 times every 2-4 weeks on different days.
+      - Hours that might give a good coverage in Europe, the US (East
+        and West coast), and a bit of South-East Asia are 12:00 and
+        18:00 UTC.
+      - My understanding is that TweetDeck displays the time as it is on
+        your computer, so UTC if you are in Tails.