Check if date goes backwards

beaglebone.txt

@@ -1003,13 +1003,38 @@ make install
 If you get errors during the /configure/ stage then you may need to reboot so that some of the installed dependencies take effect.
 
 #+BEGIN_SRC: bash
+editor /usr/bin/updatedate
+#+END_SRC
+
+Add the following:
+
+#+BEGIN_SRC: bash
+#!/bin/bash
+
+TIMESOURCE=www.ptb.de
+LOGFILE=/var/log/tlsdate.log
+DATE_BEFORE=$(date)
+YEAR_BEFORE=$(echo $DATE_BEFORE | awk -F ' ' '{print $6}')
+/usr/bin/timeout 3 tlsdate -l -t -H $TIMESOURCE -p 443
+DATE_AFTER=$(date)
+YEAR_AFTER=$(echo $DATE_AFTER | awk -F ' ' '{print $6}')
+if [ "$YEAR_AFTER" -lt "$YEAR_BEFORE" ]; then
+	echo "Incorrect date: $DATE_BEFORE -> $DATE_AFTER" >> $LOGFILE
+	date -s "DATE_BEFORE"
+fi
+#+END_SRC
+
+Save and exit.
+
+#+BEGIN_SRC: bash
+chmod +x /usr/bin/updatedate
 editor /etc/crontab
 #+END_SRC
 
 Add the following near the top of the list of tasks.
 
 #+BEGIN_SRC: bash
-*/15           * *   *   *   root /usr/bin/timeout 3 tlsdate -l -t -H www.ptb.de -p 443
+*/15           * *   *   *   root /usr/bin/updatedate
 #+END_SRC
 
 Save and exit.