diff --git a/WINGs/po/fy.po b/WINGs/po/fy.po
index 9d19c68b..b999f49c 100644
--- a/WINGs/po/fy.po
+++ b/WINGs/po/fy.po
@@ -1,5 +1,5 @@
 # Translation into Western Frisian for Window Maker
-# Copyright (C) 2015-2016 Window Maker Developers Team
+# Copyright (C) 2015-2019 Window Maker Developers Team
 # This file is distributed under the same license as the windowmaker package.
 # Original by Alwin <translations@ziggo.nl>, 2015.
 #
diff --git a/WINGs/po/nl.po b/WINGs/po/nl.po
index 9bab4757..89b99b4a 100644
--- a/WINGs/po/nl.po
+++ b/WINGs/po/nl.po
@@ -1,5 +1,5 @@
 # New translation into Dutch for Window Maker
-# Copyright (C) 2014-2015 Window Maker Developers Team
+# Copyright (C) 2014-2019 Window Maker Developers Team
 # This file is distributed under the same license as the windowmaker package.
 # Original by Alwin <translations@ziggo.nl>, 2014.
 #
diff --git a/WPrefs.app/Expert.c b/WPrefs.app/Expert.c
index 3a765c60..5a0fa2a6 100644
--- a/WPrefs.app/Expert.c
+++ b/WPrefs.app/Expert.c
@@ -2,7 +2,7 @@
  *
  *  WPrefs - Window Maker Preferences Program
  *
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *  Copyright (c) 1998-2003 Alfredo K. Kojima
  *
  *  This program is free software; you can redistribute it and/or modify
diff --git a/configure.ac b/configure.ac
index f5567ac1..dbde9292 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@ dnl ============================================================================
 dnl
 dnl Window Maker autoconf input
 dnl
-AC_COPYRIGHT([Copyright (c) 2001-2015 The Window Maker Team])
+AC_COPYRIGHT([Copyright (c) 2001-2023 The Window Maker Team])
 dnl
 dnl ============================================================================
 dnl
diff --git a/m4/wm_i18n.m4 b/m4/wm_i18n.m4
index f645065d..460a5d36 100644
--- a/m4/wm_i18n.m4
+++ b/m4/wm_i18n.m4
@@ -1,7 +1,7 @@
 # wm_i18n.m4 - Macros to check and enable translations in WindowMaker
 #
 # Copyright (c) 2014-2015 Christophe CURIS
-# Copyright (c) 2015 The Window Maker Tean
+# Copyright (c) 2015-2021 The Window Maker Tean
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/m4/wm_libexif.m4 b/m4/wm_libexif.m4
index 70bc7045..1afd6cfb 100644
--- a/m4/wm_libexif.m4
+++ b/m4/wm_libexif.m4
@@ -1,6 +1,6 @@
 # wm_libexif.m4 - Macros to check proper libexif
 #
-# Copyright (c) 2014 Window Maker Team
+# Copyright (c) 2014-2015 Window Maker Team
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
diff --git a/po/fy.po b/po/fy.po
index 990ff47a..e9941f55 100644
--- a/po/fy.po
+++ b/po/fy.po
@@ -1,5 +1,5 @@
 # Translation into Western Frisian for Window Maker
-# Copyright (C) 2015-2016 Window Maker Developers Team
+# Copyright (C) 2015-2020 Window Maker Developers Team
 # This file is distributed under the same license as the windowmaker package.
 # Original by Alwin <translations@ziggo.nl>, 2015.
 #
diff --git a/po/nl.po b/po/nl.po
index cad584e7..89c598d6 100644
--- a/po/nl.po
+++ b/po/nl.po
@@ -1,5 +1,5 @@
 # New translation into Dutch for Window Maker
-# Copyright (C) 2014-2016 Window Maker Developers Team
+# Copyright (C) 2014-2020 Window Maker Developers Team
 # This file is distributed under the same license as the windowmaker package.
 # Original by Alwin <translations@ziggo.nl>, 2014.
 #
diff --git a/script/generate-mapfile-from-header.sh b/script/generate-mapfile-from-header.sh
index ef5767b9..e643ca50 100755
--- a/script/generate-mapfile-from-header.sh
+++ b/script/generate-mapfile-from-header.sh
@@ -4,7 +4,7 @@
 #  Window Maker window manager
 #
 #  Copyright (c) 2014 Christophe CURIS
-#  Copyright (c) 2014 Window Maker Team
+#  Copyright (c) 2014-2015 Window Maker Team
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
diff --git a/script/generate-txt-from-texi.sh b/script/generate-txt-from-texi.sh
index 695b024a..dcb39760 100755
--- a/script/generate-txt-from-texi.sh
+++ b/script/generate-txt-from-texi.sh
@@ -4,7 +4,7 @@
 #  Window Maker window manager
 #
 #  Copyright (c) 2014-2015 Christophe CURIS
-#  Copyright (c) 2015 Window Maker Team
+#  Copyright (c) 2015-2019 Window Maker Team
 #
 #  This program is free software; you can redistribute it and/or modify
 #  it under the terms of the GNU General Public License as published by
diff --git a/src/WindowMaker.h b/src/WindowMaker.h
index 823f3990..dffa9167 100644
--- a/src/WindowMaker.h
+++ b/src/WindowMaker.h
@@ -2,7 +2,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/actions.c b/src/actions.c
index c1d61424..09e78f89 100644
--- a/src/actions.c
+++ b/src/actions.c
@@ -4,7 +4,7 @@
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
  *  Copyright (c) 1998-2003 Dan Pascu
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/balloon.c b/src/balloon.c
index e649f981..bc47c38a 100644
--- a/src/balloon.c
+++ b/src/balloon.c
@@ -2,7 +2,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1998-2003 Alfredo K. Kojima
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2016 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/defaults.c b/src/defaults.c
index f6120f2c..40344ae9 100644
--- a/src/defaults.c
+++ b/src/defaults.c
@@ -4,7 +4,7 @@
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
  *  Copyright (c) 1998-2003 Dan Pascu
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
 
  *
  *  This program is free software; you can redistribute it and/or modify
diff --git a/src/dialog.c b/src/dialog.c
index 0561dc1f..8f9732c4 100644
--- a/src/dialog.c
+++ b/src/dialog.c
@@ -4,7 +4,7 @@
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
  *  Copyright (c) 1998-2003 Dan Pascu
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/event.c b/src/event.c
index c33f239f..6b160dd1 100644
--- a/src/event.c
+++ b/src/event.c
@@ -3,7 +3,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/keybind.h b/src/keybind.h
index fb32f42b..b0680d34 100644
--- a/src/keybind.h
+++ b/src/keybind.h
@@ -2,7 +2,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/misc.h b/src/misc.h
index 4809f24a..dbfc1873 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -2,7 +2,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2013 Window Maker Team
+ *  Copyright (c) 2013-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/placement.h b/src/placement.h
index e959961b..37d2441e 100644
--- a/src/placement.h
+++ b/src/placement.h
@@ -3,7 +3,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2013 Window Maker Team
+ *  Copyright (c) 2013-2016 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/rootmenu.c b/src/rootmenu.c
index 05705477..213c30e8 100644
--- a/src/rootmenu.c
+++ b/src/rootmenu.c
@@ -4,7 +4,7 @@
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
  *  Copyright (c) 1998-2003 Dan Pascu
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2023 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/wsmap.c b/src/wsmap.c
index 29eda32c..064f8df9 100644
--- a/src/wsmap.c
+++ b/src/wsmap.c
@@ -2,7 +2,7 @@
  *
  *  Window Maker window manager
  *
- *  Copyright (c) 2014 Window Maker Team - David Maciejak
+ *  Copyright (c) 2014-2023 Window Maker Team - David Maciejak
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/src/xdnd.c b/src/xdnd.c
index 63e6d9c3..6ea26c5d 100644
--- a/src/xdnd.c
+++ b/src/xdnd.c
@@ -2,7 +2,7 @@
  *  Window Maker window manager
  *
  *  Copyright (c) 1997-2003 Alfredo K. Kojima
- *  Copyright (c) 2014 Window Maker Team
+ *  Copyright (c) 2014-2015 Window Maker Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/util/wmiv.c b/util/wmiv.c
index 7717baf3..389075d7 100755
--- a/util/wmiv.c
+++ b/util/wmiv.c
@@ -1,7 +1,7 @@
 /*
  *  Window Maker window manager
  *
- *  Copyright (c) 2014 Window Maker Team - David Maciejak
+ *  Copyright (c) 2014-2023 Window Maker Team - David Maciejak
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
diff --git a/wrlib/flip.c b/wrlib/flip.c
index b884ab58..13b10961 100644
--- a/wrlib/flip.c
+++ b/wrlib/flip.c
@@ -2,7 +2,7 @@
  *
  * Raster graphics library
  *
- * Copyright (c) 2014 Window Maker Team
+ * Copyright (c) 2014-2021 Window Maker Team
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
diff --git a/wrlib/load.c b/wrlib/load.c
index 016a22ee..1f94f0e4 100644
--- a/wrlib/load.c
+++ b/wrlib/load.c
@@ -3,7 +3,7 @@
  * Raster graphics library
  *
  * Copyright (c) 1997-2003 Alfredo K. Kojima
- * Copyright (c) 2014 Window Maker Team
+ * Copyright (c) 2014-2021 Window Maker Team
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
diff --git a/wrlib/load_magick.c b/wrlib/load_magick.c
index d7ff6941..5602d64d 100644
--- a/wrlib/load_magick.c
+++ b/wrlib/load_magick.c
@@ -2,7 +2,7 @@
  *
  * Raster graphics library
  *
- * Copyright (c) 2014 Window Maker Team
+ * Copyright (c) 2014-2021 Window Maker Team
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
diff --git a/wrlib/load_ppm.c b/wrlib/load_ppm.c
index 3b2d5b1e..2f01c8ad 100644
--- a/wrlib/load_ppm.c
+++ b/wrlib/load_ppm.c
@@ -3,7 +3,7 @@
  * Raster graphics library
  *
  * Copyright (c) 1997-2003 Alfredo K. Kojima
- * Copyright (c) 2014 Window Maker Team
+ * Copyright (c) 2014-2021 Window Maker Team
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
diff --git a/wrlib/load_webp.c b/wrlib/load_webp.c
index 35996820..ac8ff4f7 100644
--- a/wrlib/load_webp.c
+++ b/wrlib/load_webp.c
@@ -2,7 +2,7 @@
  *
  * Raster graphics library
  *
- * Copyright (c) 2014 Window Maker Team
+ * Copyright (c) 2014-2021 Window Maker Team
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
diff --git a/wrlib/load_xpm.c b/wrlib/load_xpm.c
index f2c433cb..54697acf 100644
--- a/wrlib/load_xpm.c
+++ b/wrlib/load_xpm.c
@@ -3,7 +3,7 @@
  * Raster graphics library
  *
  * Copyright (c) 1997-2003 Alfredo K. Kojima
- * Copyright (c) 2014 Window Maker Team
+ * Copyright (c) 2014-2021 Window Maker Team
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public