gnu: date: Fix build with newer tzdata.

* gnu/packages/patches/date-ignore-zonenow.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/calendar.scm (date): Use it.

Change-Id: I29bdfb49237650706abd870f2b9875739d12c6d5

gnu/local.mk

@@ -1115,6 +1115,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/cvs-CVE-2017-12836.patch		\
   %D%/packages/patches/d-feet-drop-unused-meson-argument.patch	\
   %D%/packages/patches/dante-non-darwin.patch			\
+  %D%/packages/patches/date-ignore-zonenow.patch	\
   %D%/packages/patches/date-output-pkg-config-files.patch	\
   %D%/packages/patches/datefudge-gettimeofday.patch		\
   %D%/packages/patches/dbacl-include-locale.h.patch		\

gnu/packages/calendar.scm

@@ -85,7 +85,8 @@
          (patches
           ;; Install pkg-config files
           ;; https://github.com/HowardHinnant/date/pull/538
-          (search-patches "date-output-pkg-config-files.patch"))))
+          (search-patches "date-ignore-zonenow.patch"
+                          "date-output-pkg-config-files.patch"))))
       (inputs (list tzdata))
       (build-system cmake-build-system)
       (arguments

gnu/packages/patches/date-ignore-zonenow.patch

@@ -0,0 +1,13 @@
+Ignore the new zonenow.tab file introduced in tzdata 2023d.
+
+diff -u a/src/tz.cpp b/src/tz.cpp
+--- a/src/tz.cpp	2024-03-08 11:14:14.822488065 +0100
++++ b/src/tz.cpp	2024-03-08 11:47:12.105268426 +0100
+@@ -2667,6 +2667,7 @@
+                 strcmp(d->d_name, "right")        == 0      ||
+                 strcmp(d->d_name, "+VERSION")     == 0      ||
+                 strcmp(d->d_name, "zone.tab")     == 0      ||
++                strcmp(d->d_name, "zonenow.tab")  == 0      ||
+                 strcmp(d->d_name, "zone1970.tab") == 0      ||
+                 strcmp(d->d_name, "tzdata.zi")    == 0      ||
+                 strcmp(d->d_name, "leapseconds")  == 0      ||