Debug & Review · LOCAL TOOL

Timestamp Alignment Desk

Compare timestamp lines as explicit Unix seconds, Unix milliseconds, or ISO date-times with a timezone. Auto mode shows both numeric interpretations instead of guessing a unit.

Runs in this page
No API call

WORKSPACEINPUT → RESULT

Your input

LOCAL

Result

Run the tool to see a result.

Your result will appear here. Input is not saved.

Browser-side processingNothing is sent to a tool API.

WHY THIS TOOL EXISTS

A focused job, not a black box.

The report makes a common seconds-versus-milliseconds mistake visible and preserves line-specific errors. A local timezone is never silently attached to a zone-less date-time.

How to use it

Paste one timestamp per line.
Choose a numeric unit when the source format is known.
Compare UTC results and review invalid or ambiguous lines.

TRY A WORKING EXAMPLE

Start with known input.

Load this sample into the workspace, run the tool, and compare the result shown below.

Show sample input

{
  "source": "1767225600\n2026-01-01T08:00:00+08:00\n2026-02-30T00:00:00Z",
  "unit": "Auto (flag ambiguity)"
}

Expected sample result from the local tool

3 timestamp(s) reviewed.

{
  "records": [
    {
      "line": 1,
      "input": "1767225600",
      "status": "ambiguous numeric unit",
      "secondsCandidate": "2026-01-01T00:00:00.000Z",
      "millisecondsCandidate": "1970-01-21T10:53:45.600Z"
    },
    {
      "line": 2,
      "input": "2026-01-01T08:00:00+08:00",
      "utc": "2026-01-01T00:00:00.000Z",
      "epochMilliseconds": 1767225600000
    },
    {
      "line": 3,
      "input": "2026-02-30T00:00:00Z",
      "error": "Invalid calendar date, time, or offset."
    }
  ]
}

Numeric units are never guessed in Auto mode. Explicit-zone ISO inputs are normalized to UTC.

LIMITS AND INTERPRETATION

What the result cannot tell you.

ISO inputs need seconds and an explicit Z or ±HH:MM zone; fractional seconds support up to three digits. Leap seconds and named timezones are not supported. Results follow JavaScript Date millisecond precision.

Inputs are processed in this page and are not written to local storage.