diff --git a/License.txt b/License.txt
index 78512d18..63670e4a 100644
--- a/License.txt
+++ b/License.txt
@@ -4,7 +4,7 @@
 
 Libxlsxwriter is released under a FreeBSD license:
 
-    Copyright 2014-2017, John McNamara <jmcnamara@cpan.org>
+    Copyright 2014-2018, John McNamara <jmcnamara@cpan.org>
     All rights reserved.
 
     Redistribution and use in source and binary forms, with or without
diff --git a/Makefile b/Makefile
index 426e3355..39ec6b96 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 # Keep the output quiet by default.
diff --git a/dev/release/fix_example_docs.pl b/dev/release/fix_example_docs.pl
index 6a3c3494..a0d7b16d 100644
--- a/dev/release/fix_example_docs.pl
+++ b/dev/release/fix_example_docs.pl
@@ -4,7 +4,7 @@
 # Simple program to arrange the example programs in a user defined order
 # instead or sorted order. Also add a caption.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 use warnings;
 use strict;
diff --git a/dev/release/fix_example_links.pl b/dev/release/fix_example_links.pl
index 8cd65fa5..b04a0c9b 100644
--- a/dev/release/fix_example_links.pl
+++ b/dev/release/fix_example_links.pl
@@ -4,7 +4,7 @@
 # Simple program to generate the examples.dox file from a simple text file,
 # with links to the next/previous examples.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 use strict;
 use warnings;
diff --git a/dev/release/gen_error_strings.pl b/dev/release/gen_error_strings.pl
index ac9dbf57..2a962753 100644
--- a/dev/release/gen_error_strings.pl
+++ b/dev/release/gen_error_strings.pl
@@ -6,7 +6,7 @@
 #
 #    perl dev/release/gen_error_strings.pl include/xlsxwriter/common.h
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 use warnings;
 use strict;
diff --git a/dev/release/gen_umbrella_file.pl b/dev/release/gen_umbrella_file.pl
index f32481b7..1de0143e 100644
--- a/dev/release/gen_umbrella_file.pl
+++ b/dev/release/gen_umbrella_file.pl
@@ -4,7 +4,7 @@
 # Simple program to generate the coccoapods unbrella file.
 # Run from the libxlsxwriter root dir.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 use warnings;
 use strict;
diff --git a/dev/release/gen_windows_def_file.pl b/dev/release/gen_windows_def_file.pl
index c13be733..8b2ff979 100644
--- a/dev/release/gen_windows_def_file.pl
+++ b/dev/release/gen_windows_def_file.pl
@@ -6,7 +6,7 @@
 #
 #    perl dev/release/gen_windows_def_file.pl lib/libxlsxwriter.a
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 use warnings;
 use strict;
diff --git a/docs/Makefile b/docs/Makefile
index 1c2e33f5..384d410a 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 # Keep the output quiet by default.
diff --git a/docs/footer.html b/docs/footer.html
index 3358f448..a3b2dbed 100644
--- a/docs/footer.html
+++ b/docs/footer.html
@@ -4,7 +4,7 @@
 <div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
   <ul>
     $navpath
-    <li class="footer">Copyright 2014-2017 John McNamara. $generatedby
+    <li class="footer">Copyright 2014-2018 John McNamara. $generatedby
     <a href="http://www.doxygen.org/index.html">
     <img class="footer" src="$relpath^doxygen.png" alt="doxygen"/></a></li>
   </ul>
@@ -12,7 +12,7 @@
 <!--END GENERATE_TREEVIEW-->
 <!--BEGIN !GENERATE_TREEVIEW-->
 <hr class="footer"/><address class="footer"><small>
-Copyright 2014-2017 John McNamara.
+Copyright 2014-2018 John McNamara.
 $generatedby <a href="http://www.doxygen.org/index.html">
 <img class="footer" src="$relpath^doxygen.png" alt="doxygen"/>
 </a>
diff --git a/include/xlsxwriter.h b/include/xlsxwriter.h
index 4a88fbfd..7ce2aad7 100644
--- a/include/xlsxwriter.h
+++ b/include/xlsxwriter.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  */
 
 /**
diff --git a/include/xlsxwriter/app.h b/include/xlsxwriter/app.h
index 27cb4ff9..51121538 100644
--- a/include/xlsxwriter/app.h
+++ b/include/xlsxwriter/app.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * app - A libxlsxwriter library for creating Excel XLSX app files.
  *
diff --git a/include/xlsxwriter/chart.h b/include/xlsxwriter/chart.h
index e3f16c3f..52787401 100644
--- a/include/xlsxwriter/chart.h
+++ b/include/xlsxwriter/chart.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * chart - A libxlsxwriter library for creating Excel XLSX chart files.
  *
diff --git a/include/xlsxwriter/common.h b/include/xlsxwriter/common.h
index efd6951b..b3de7b66 100644
--- a/include/xlsxwriter/common.h
+++ b/include/xlsxwriter/common.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  */
 
 /**
@@ -9,7 +9,7 @@
  *
  * @brief Common functions and defines for the libxlsxwriter library.
  *
- * <!-- Copyright 2014-2017, John McNamara, jmcnamara@cpan.org -->
+ * <!-- Copyright 2014-2018, John McNamara, jmcnamara@cpan.org -->
  *
  */
 #ifndef __LXW_COMMON_H__
diff --git a/include/xlsxwriter/content_types.h b/include/xlsxwriter/content_types.h
index b91f2a87..7caa85e3 100644
--- a/include/xlsxwriter/content_types.h
+++ b/include/xlsxwriter/content_types.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * content_types - A libxlsxwriter library for creating Excel XLSX
  *                 content_types files.
diff --git a/include/xlsxwriter/core.h b/include/xlsxwriter/core.h
index 0d114525..fab165b2 100644
--- a/include/xlsxwriter/core.h
+++ b/include/xlsxwriter/core.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * core - A libxlsxwriter library for creating Excel XLSX core files.
  *
diff --git a/include/xlsxwriter/custom.h b/include/xlsxwriter/custom.h
index a5411a72..c552c0d1 100644
--- a/include/xlsxwriter/custom.h
+++ b/include/xlsxwriter/custom.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * custom - A libxlsxwriter library for creating Excel custom property files.
  *
diff --git a/include/xlsxwriter/drawing.h b/include/xlsxwriter/drawing.h
index c6c5e116..0455fe04 100644
--- a/include/xlsxwriter/drawing.h
+++ b/include/xlsxwriter/drawing.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * drawing - A libxlsxwriter library for creating Excel XLSX drawing files.
  *
diff --git a/include/xlsxwriter/format.h b/include/xlsxwriter/format.h
index dcee3e44..a73c2d74 100644
--- a/include/xlsxwriter/format.h
+++ b/include/xlsxwriter/format.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  */
 
 /**
diff --git a/include/xlsxwriter/hash_table.h b/include/xlsxwriter/hash_table.h
index fcba0ba0..44ab3a2b 100644
--- a/include/xlsxwriter/hash_table.h
+++ b/include/xlsxwriter/hash_table.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * hash_table - Hash table functions for libxlsxwriter.
  *
diff --git a/include/xlsxwriter/packager.h b/include/xlsxwriter/packager.h
index f332ba06..e57438f5 100644
--- a/include/xlsxwriter/packager.h
+++ b/include/xlsxwriter/packager.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * packager - A libxlsxwriter library for creating Excel XLSX packager files.
  *
diff --git a/include/xlsxwriter/relationships.h b/include/xlsxwriter/relationships.h
index c1431e93..ea9972f5 100644
--- a/include/xlsxwriter/relationships.h
+++ b/include/xlsxwriter/relationships.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * relationships - A libxlsxwriter library for creating Excel XLSX
  *                 relationships files.
diff --git a/include/xlsxwriter/shared_strings.h b/include/xlsxwriter/shared_strings.h
index 97b857e4..049c5612 100644
--- a/include/xlsxwriter/shared_strings.h
+++ b/include/xlsxwriter/shared_strings.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * shared_strings - A libxlsxwriter library for creating Excel XLSX
  *                  sst files.
diff --git a/include/xlsxwriter/styles.h b/include/xlsxwriter/styles.h
index 52b819cc..93edae1e 100644
--- a/include/xlsxwriter/styles.h
+++ b/include/xlsxwriter/styles.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * styles - A libxlsxwriter library for creating Excel XLSX styles files.
  *
diff --git a/include/xlsxwriter/theme.h b/include/xlsxwriter/theme.h
index 79791e4b..c589ff28 100644
--- a/include/xlsxwriter/theme.h
+++ b/include/xlsxwriter/theme.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * theme - A libxlsxwriter library for creating Excel XLSX theme files.
  *
diff --git a/include/xlsxwriter/utility.h b/include/xlsxwriter/utility.h
index 5a76025e..76f25927 100644
--- a/include/xlsxwriter/utility.h
+++ b/include/xlsxwriter/utility.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  */
 
 /**
@@ -9,7 +9,7 @@
  *
  * @brief Utility functions for libxlsxwriter.
  *
- * <!-- Copyright 2014-2017, John McNamara, jmcnamara@cpan.org -->
+ * <!-- Copyright 2014-2018, John McNamara, jmcnamara@cpan.org -->
  *
  */
 
diff --git a/include/xlsxwriter/workbook.h b/include/xlsxwriter/workbook.h
index 46cf8c5a..a4e721f9 100644
--- a/include/xlsxwriter/workbook.h
+++ b/include/xlsxwriter/workbook.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  */
 
 /**
diff --git a/include/xlsxwriter/worksheet.h b/include/xlsxwriter/worksheet.h
index 530b7705..dc4442bd 100644
--- a/include/xlsxwriter/worksheet.h
+++ b/include/xlsxwriter/worksheet.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  */
 
 /**
diff --git a/include/xlsxwriter/xmlwriter.h b/include/xlsxwriter/xmlwriter.h
index b6dad62a..0dc45a5b 100644
--- a/include/xlsxwriter/xmlwriter.h
+++ b/include/xlsxwriter/xmlwriter.h
@@ -1,7 +1,7 @@
 /*
  * libxlsxwriter
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  * xmlwriter - A libxlsxwriter library for creating Excel XLSX
  *             XML files.
diff --git a/src/Makefile b/src/Makefile
index 505e79b2..71f237a0 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 # Keep the output quiet by default.
diff --git a/src/app.c b/src/app.c
index 2270a513..7ec91fb0 100644
--- a/src/app.c
+++ b/src/app.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/chart.c b/src/chart.c
index d1bbe2d8..f0f75adf 100644
--- a/src/chart.c
+++ b/src/chart.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/content_types.c b/src/content_types.c
index 2040c352..73068bd4 100644
--- a/src/content_types.c
+++ b/src/content_types.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/core.c b/src/core.c
index cda1beee..d96f9510 100644
--- a/src/core.c
+++ b/src/core.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/custom.c b/src/custom.c
index 7dd70af9..0323dedc 100644
--- a/src/custom.c
+++ b/src/custom.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/drawing.c b/src/drawing.c
index 27ed28ac..1cde1d51 100644
--- a/src/drawing.c
+++ b/src/drawing.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/format.c b/src/format.c
index 9e6b2b17..2bf5f8f6 100644
--- a/src/format.c
+++ b/src/format.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/hash_table.c b/src/hash_table.c
index 6aca28df..36fa59ec 100644
--- a/src/hash_table.c
+++ b/src/hash_table.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/packager.c b/src/packager.c
index d4e4705f..743bdf2f 100644
--- a/src/packager.c
+++ b/src/packager.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/relationships.c b/src/relationships.c
index b88fae79..67f85cc8 100644
--- a/src/relationships.c
+++ b/src/relationships.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/shared_strings.c b/src/shared_strings.c
index c4b16a84..5dc34c8b 100644
--- a/src/shared_strings.c
+++ b/src/shared_strings.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/styles.c b/src/styles.c
index 234523f4..326e27c3 100644
--- a/src/styles.c
+++ b/src/styles.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/theme.c b/src/theme.c
index 7a67fe3d..35af49c7 100644
--- a/src/theme.c
+++ b/src/theme.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/utility.c b/src/utility.c
index ecc7b2e0..0883857f 100644
--- a/src/utility.c
+++ b/src/utility.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/workbook.c b/src/workbook.c
index 25c2591c..55dab5db 100644
--- a/src/workbook.c
+++ b/src/workbook.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/worksheet.c b/src/worksheet.c
index 99e3dc10..ce2d7797 100644
--- a/src/worksheet.c
+++ b/src/worksheet.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/src/xmlwriter.c b/src/xmlwriter.c
index c30d322a..48701bf1 100644
--- a/src/xmlwriter.c
+++ b/src/xmlwriter.c
@@ -3,7 +3,7 @@
  *
  * Used in conjunction with the libxlsxwriter library.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org. See LICENSE.txt.
  *
  */
 
diff --git a/test/functional/base_test_class.py b/test/functional/base_test_class.py
index 6733a69a..1add172f 100644
--- a/test/functional/base_test_class.py
+++ b/test/functional/base_test_class.py
@@ -2,7 +2,7 @@
 #
 # Base test class for libxlsxwriter functional tests.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 import unittest
diff --git a/test/functional/helper_functions.py b/test/functional/helper_functions.py
index 10e73ab5..ea310312 100644
--- a/test/functional/helper_functions.py
+++ b/test/functional/helper_functions.py
@@ -2,7 +2,7 @@
 #
 # Helper functions for testing libxlsxwriter.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 import re
diff --git a/test/functional/src/Makefile b/test/functional/src/Makefile
index 874fef4a..f4d13b09 100644
--- a/test/functional/src/Makefile
+++ b/test/functional/src/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter functional test executables.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 # Keep the output quiet by default.
diff --git a/test/unit/Makefile b/test/unit/Makefile
index 37082b37..adb6accc 100644
--- a/test/unit/Makefile
+++ b/test/unit/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 # Keep the output quiet by default.
diff --git a/test/unit/Makefile.unit b/test/unit/Makefile.unit
index 0bbcb7e7..eacfb30a 100644
--- a/test/unit/Makefile.unit
+++ b/test/unit/Makefile.unit
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 # Keep the output quiet by default.
diff --git a/test/unit/app/Makefile b/test/unit/app/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/app/Makefile
+++ b/test/unit/app/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/app/main.c b/test/unit/app/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/app/main.c
+++ b/test/unit/app/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/chart/Makefile b/test/unit/chart/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/chart/Makefile
+++ b/test/unit/chart/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/chart/main.c b/test/unit/chart/main.c
index 8053799b..3431d9e3 100644
--- a/test/unit/chart/main.c
+++ b/test/unit/chart/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017 John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018 John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/content_types/Makefile b/test/unit/content_types/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/content_types/Makefile
+++ b/test/unit/content_types/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/content_types/main.c b/test/unit/content_types/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/content_types/main.c
+++ b/test/unit/content_types/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/core/Makefile b/test/unit/core/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/core/Makefile
+++ b/test/unit/core/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/core/main.c b/test/unit/core/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/core/main.c
+++ b/test/unit/core/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/custom/Makefile b/test/unit/custom/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/custom/Makefile
+++ b/test/unit/custom/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/custom/main.c b/test/unit/custom/main.c
index 8053799b..3431d9e3 100644
--- a/test/unit/custom/main.c
+++ b/test/unit/custom/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017 John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018 John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/drawing/Makefile b/test/unit/drawing/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/drawing/Makefile
+++ b/test/unit/drawing/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/drawing/main.c b/test/unit/drawing/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/drawing/main.c
+++ b/test/unit/drawing/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/relationships/Makefile b/test/unit/relationships/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/relationships/Makefile
+++ b/test/unit/relationships/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/relationships/main.c b/test/unit/relationships/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/relationships/main.c
+++ b/test/unit/relationships/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/sst/Makefile b/test/unit/sst/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/sst/Makefile
+++ b/test/unit/sst/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/sst/main.c b/test/unit/sst/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/sst/main.c
+++ b/test/unit/sst/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/styles/Makefile b/test/unit/styles/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/styles/Makefile
+++ b/test/unit/styles/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/styles/main.c b/test/unit/styles/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/styles/main.c
+++ b/test/unit/styles/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/utility/Makefile b/test/unit/utility/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/utility/Makefile
+++ b/test/unit/utility/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/utility/main.c b/test/unit/utility/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/utility/main.c
+++ b/test/unit/utility/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/workbook/Makefile b/test/unit/workbook/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/workbook/Makefile
+++ b/test/unit/workbook/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/workbook/main.c b/test/unit/workbook/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/workbook/main.c
+++ b/test/unit/workbook/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/worksheet/Makefile b/test/unit/worksheet/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/worksheet/Makefile
+++ b/test/unit/worksheet/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/worksheet/main.c b/test/unit/worksheet/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/worksheet/main.c
+++ b/test/unit/worksheet/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN
diff --git a/test/unit/xmlwriter/Makefile b/test/unit/xmlwriter/Makefile
index e9101f9b..806c4723 100644
--- a/test/unit/xmlwriter/Makefile
+++ b/test/unit/xmlwriter/Makefile
@@ -2,7 +2,7 @@
 #
 # Makefile for libxlsxwriter library.
 #
-# Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+# Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
 #
 
 include ../Makefile.unit
diff --git a/test/unit/xmlwriter/main.c b/test/unit/xmlwriter/main.c
index 8b5e536e..14265143 100644
--- a/test/unit/xmlwriter/main.c
+++ b/test/unit/xmlwriter/main.c
@@ -1,7 +1,7 @@
 /*
  * Test runner for xmlwriter using ctest.
  *
- * Copyright 2014-2017, John McNamara, jmcnamara@cpan.org
+ * Copyright 2014-2018, John McNamara, jmcnamara@cpan.org
  *
  */
 #define CTEST_MAIN