tools: add timezone update workflow

Fixes: https://github.com/nodejs/node/issues/43134
PR-URL: https://github.com/nodejs/node/pull/43988
Reviewed-By: Steven R Loomis <srloomis@us.ibm.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/tools/update-timezone.mjs b/tools/update-timezone.mjs
new file mode 100755
index 00000000000..33da42f4e98
--- /dev/null
+++ b/tools/update-timezone.mjs
@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+// Usage: tools/update-timezone.mjs
+import { execSync, spawnSync } from 'node:child_process';
+import { renameSync, readdirSync, rmSync } from 'node:fs';
+import { exit } from 'node:process';
+
+const fileNames = [
+  'zoneinfo64.res',
+  'windowsZones.res',
+  'timezoneTypes.res',
+  'metaZones.res',
+];
+
+const availableVersions = readdirSync('icu-data/tzdata/icunew', { withFileTypes: true })
+.filter((dirent) => dirent.isDirectory())
+.map((dirent) => dirent.name);
+
+const currentVersion = process.versions.tz;
+const latestVersion = availableVersions.sort().at(-1);
+
+if (latestVersion === currentVersion) {
+  console.log(`Terminating early, tz version is latest @ ${currentVersion}`);
+  exit();
+}
+
+execSync('bzip2 -d deps/icu-small/source/data/in/icudt*.dat.bz2');
+fileNames.forEach((file) => {
+  renameSync(`icu-data/tzdata/icunew/${latestVersion}/44/le/${file}`, `deps/icu-small/source/data/in/${file}`);
+  spawnSync(
+    'icupkg', [
+      '-a',
+      file,
+      'icudt*.dat',
+    ], { cwd: 'deps/icu-small/source/data/in/' }
+  );
+  rmSync(`deps/icu-small/source/data/in/${file}`);
+});
+execSync('bzip2 -z deps/icu-small/source/data/in/icudt*.dat');
+rmSync('icu-data', { recursive: true });