use tinyduration for ISO8601 parsing and serializing

pnpm-lock.yaml

@@ -59,6 +59,9 @@ importers:
       tailwindcss-animate:
         specifier: ^1.0.7
         version: 1.0.7(tailwindcss@4.1.11)
+      tinyduration:
+        specifier: ^3.4.1
+        version: 3.4.1
     devDependencies:
       '@eslint/compat':
         specifier: ^1.2.5
@@ -1539,6 +1542,9 @@ packages:
     resolution: {integrity: sha512-5S7Va8hKfV7W5U6g3aYxXmlPoZVAwUMy9AOKyF2fVuZa2UD3qZjg578OrLRt8PcNN1PleVaL/5/yYATNL0ICUw==}
     engines: {node: '>=18'}
 
+  tinyduration@3.4.1:
+    resolution: {integrity: sha512-NemFoamVYn7TmtwZKZ3OiliM9fZkr6EWiTM+wKknco6POSy2gS689xx/pXip0JYp40HXpUw6k65CUYHWYUXdaA==}
+
   tinyglobby@0.2.14:
     resolution: {integrity: sha512-tX5e7OM1HnYr2+a2C/4V0htOcSQcoSTH9KgJnVvNm5zm/cyEWKJ7j7YutsH9CxMdtOkkLFy2AHrMci9IM8IPZQ==}
     engines: {node: '>=12.0.0'}
@@ -2917,6 +2923,8 @@ snapshots:
       mkdirp: 3.0.1
       yallist: 5.0.0
 
+  tinyduration@3.4.1: {}
+
   tinyglobby@0.2.14:
     dependencies:
       fdir: 6.4.6(picomatch@4.0.3)