https://bugs.gentoo.org/925503

Call coreutils date instead of a Python script.
--- a/meson.build
+++ b/meson.build
@@ -104,17 +104,16 @@ cxx.check_header('charconv', required:true)
 build_aux = join_paths(meson.current_source_dir(), 'build-aux')
 ################################################################################
 # derived date values (based on 'mu-date'); used in docs
-# we can't use the 'date' because MacOS 'date' is incompatible with GNU's.
-pdate=find_program(join_paths(build_aux, 'date.py'))
+date=find_program('date', required:true)
 env = environment()
 env.set('LANG', 'C')
-mu_day_month_year = run_command(pdate, mu_date, '%d %B %Y',
+mu_day_month_year = run_command(date, '-u', '+%d %B %Y', '--date', mu_date,
                                 check:true, capture:true,
                                 env: env).stdout().strip()
-mu_month_year = run_command(pdate, mu_date, '%B %Y',
+mu_month_year = run_command(date, '-u', '+%B %Y', '--date', mu_date,
                             check:true, capture:true,
                             env: env).stdout().strip()
-mu_year = run_command(pdate, mu_date, '%Y',
+mu_year = run_command(date, '-u', '+%Y', '--date', mu_date,
                       check:true, capture:true, env: env).stdout().strip()
 
 ################################################################################
-- 
2.44.0