diff --git a/vnstat-1.11-there-are-only-12-months.patch b/vnstat-1.11-there-are-only-12-months.patch
new file mode 100644
index 0000000..41806c0
--- /dev/null
+++ b/vnstat-1.11-there-are-only-12-months.patch
@@ -0,0 +1,11 @@
+--- vnstat-1.11/src/vnstat.c.old	2011-06-01 00:29:51.000000000 +0200
++++ vnstat-1.11/src/vnstat.c	2013-08-07 14:42:58.396231450 +0200
+@@ -485,7 +485,7 @@
+ 			readdb(interface, dirname);
+ 
+ 			data.totalrx=data.totaltx=data.totalrxk=data.totaltxk=0;
+-			for (i=0; i<=29; i++) {
++			for (i=0; i<=12; i++) {
+ 				if (data.month[i].used) {
+ 					addtraffic(&data.totalrx, &data.totalrxk, data.month[i].rx, data.month[i].rxk);
+ 					addtraffic(&data.totaltx, &data.totaltxk, data.month[i].tx, data.month[i].txk);
diff --git a/vnstat.spec b/vnstat.spec
index 5a37a16..bfd694b 100644
--- a/vnstat.spec
+++ b/vnstat.spec
@@ -1,7 +1,7 @@
 Summary: Console-based network traffic monitor
 Name: vnstat
 Version: 1.11
-Release: 17%{?dist}
+Release: 18%{?dist}
 
 License: GPLv2
 Group: System Environment/Daemons
@@ -15,6 +15,7 @@ Requires(postun): systemd-units
 BuildRequires: gd-devel
 BuildRequires: systemd
 Patch0: vnstat-run-vnstat.diff
+Patch1: vnstat-1.11-there-are-only-12-months.patch
 
 %description
 vnStat is a console-based network traffic monitor that keeps a log of daily
@@ -25,6 +26,7 @@ be used without root permissions. See the webpage for few 'screenshots'.
 %prep
 %setup -q
 %patch0 -p1
+%patch1 -p1
 
 # disable maximum bandwidth setting and change pidfile location
 sed -i -e "s,/var/run/,/run/vnstat/,g; \
@@ -134,6 +136,11 @@ getent passwd %{name} > /dev/null || %{_sbindir}/useradd -r -g %{name} -M \
 
 
 %changelog
+* Wed Aug 07 2013 Adrian Reber <adrian@lisas.de> - 1.11-18
+- fix bogus dates
+- added patch for
+  "vnstat.c:489:22: warning: iteration 12u invokes undefined behavior [-Waggressive-loop-optimizations]"
+
 * Wed Aug 07 2013 Mathieu Bridon <bochecha@fedoraproject.org> - 1.11-17
 - Fix the build by adding the missing BR on systemd.
 
@@ -234,16 +241,16 @@ getent passwd %{name} > /dev/null || %{_sbindir}/useradd -r -g %{name} -M \
 * Fri Sep 15 2006 Adrian Reber <adrian@lisas.de> - 1.4-8
 - rebuilt
 
-* Fri Mar 18 2006 Adrian Reber <adrian@lisas.de> - 1.4-7
+* Fri Mar 17 2006 Adrian Reber <adrian@lisas.de> - 1.4-7
 - rebuilt; fixed dist tag
 
-* Fri Mar 18 2006 Adrian Reber <adrian@lisas.de> - 1.4-6
+* Fri Mar 17 2006 Adrian Reber <adrian@lisas.de> - 1.4-6
 - rebuilt
 
 * Sun May 22 2005 Jeremy Katz <katzj@redhat.com> - 1.4-5
 - rebuild on all arches
 
-* Fri Apr  7 2005 Michael Schwendt <mschwendt[AT]users.sf.net>
+* Fri Apr  8 2005 Michael Schwendt <mschwendt[AT]users.sf.net>
 - rebuilt
 
 * Mon Feb 28 2005 Adrian Reber <adrian@lisas.de> 1.4-3