--- a/debian/patches/reproducible-build	1970-01-01 01:00:00.000000000 +0100
--- b/debian/patches/reproducible-build	2016-08-19 23:39:03.014037657 +0100
@@ -0,0 +1,34 @@
+Description: Make the build reproducible
+Author: Chris Lamb <lamby@debian.org>
+Last-Update: 2016-08-19
+
+--- dacs-1.4.28b.orig/src/mkstamp
++++ dacs-1.4.28b/src/mkstamp
+@@ -18,7 +18,11 @@ version="$1"
+ 
+ echo "#define DACS_VERSION_REVID \"\$Id: \$\""
+ 
+-now=`date '+%e-%h-%Y %H:%M:%S' | sed -e "s/^ *//"`
++if test -n "$SOURCE_DATE_EPOCH"; then
++  now=`LC_ALL=C date --utc --date="@$SOURCE_DATE_EPOCH" '+%e-%h-%Y %H:%M:%S' | sed -e "s/^ *//"`
++else
++  now=`date '+%e-%h-%Y %H:%M:%S' | sed -e "s/^ *//"`
++fi
+ echo "#define DACS_VERSION_DATE \"Release date $now\""
+ 
+ echo "#define DACS_VERSION_RELEASE \"$version\""
+--- dacs-1.4.28b.orig/man/mkversion
++++ dacs-1.4.28b/man/mkversion
+@@ -20,7 +20,11 @@ textvfile="version.txt"
+ # We need the GNU cpp and this is the easiest way to ensure that
+ xcpp="gcc -E"
+ 
+-date=`date '+%e-%h-%Y' | sed -e "s/  / /"`
++if test -n "$SOURCE_DATE_EPOCH"; then
++  date=`LC_ALL=C date --utc --date="@$SOURCE_DATE_EPOCH" '+%e-%h-%Y' | sed -e "s/  / /"`
++else
++  date=`date '+%e-%h-%Y' | sed -e "s/  / /"`
++fi
+ version=`echo DACS_VERSION_RELEASE \
+             | $xcpp -P -include ../include/dacs_version.h - \
+                 | sed -e 's/"//g' | tail -1`
--- a/debian/patches/series	2016-08-19 23:00:20.526059561 +0100
--- b/debian/patches/series	2016-08-19 23:16:48.618525178 +0100
@@ -2,3 +2,4 @@
 ssl_hook_Fixup
 libtool-shell
 shared-library-linkage
+reproducible-build
--- a/man/mkindex	2016-08-19 23:00:20.538059662 +0100
--- b/man/mkindex	2016-08-19 23:52:25.516923031 +0100
@@ -474,7 +474,12 @@
 
 mkdtd "../dtd-xsd" "/dtd-xsd" >> ${f}.html
 
-now=`date`
+if test -n "$SOURCE_DATE_EPOCH"
+then
+  now=`LC_ALL=C date --utc --date="@$SOURCE_DATE_EPOCH"`
+else
+  now=`date`
+fi
 echo '</div>' >> "${f}.html"
 echo '<div id="credit-tag">' >> "${f}.html"
 echo '<hr width="66%"><center>' >> "${f}.html"