Unix Calculator
    Free · No API Key · 100 req/hour

    Unix Timestamp API

    A free REST API for timestamp conversion. Returns JSON with ISO 8601, timezone-aware output, relative time, and production warnings. No authentication required.

    CORS enabled — use from any domain

    No API key required

    Auto-detects seconds, ms, µs, ns

    Base URL

    https://unixcalculator.com/api/v1/convert

    Query Parameters

    ParameterRequiredDefaultDescription
    tsNonowUnix timestamp (seconds, ms, µs, or ns). Alias: timestamp
    tzNoUTCIANA timezone (e.g. America/New_York). Alias: timezone
    formatNofull"iso", "unix", or "full" (default)

    Live API Tester

    GET /api/v1/convert?ts=1733529600&tz=UTC

    Example requests

    Current timestamp

    GET /api/v1/convert
    curl "https://unixcalculator.com/api/v1/convert"

    Specific timestamp

    GET /api/v1/convert?ts=1733529600
    curl "https://unixcalculator.com/api/v1/convert?ts=1733529600"

    With timezone

    GET /api/v1/convert?ts=1733529600&tz=America/New_York
    curl "https://unixcalculator.com/api/v1/convert?ts=1733529600&tz=America/New_York"

    Milliseconds auto-detected

    GET /api/v1/convert?ts=1733529600000
    curl "https://unixcalculator.com/api/v1/convert?ts=1733529600000"

    ISO only (lightweight)

    GET /api/v1/convert?ts=1733529600&format=iso
    curl "https://unixcalculator.com/api/v1/convert?ts=1733529600&format=iso"

    Current time in Tokyo

    GET /api/v1/convert?tz=Asia/Tokyo
    curl "https://unixcalculator.com/api/v1/convert?tz=Asia/Tokyo"

    JavaScript (fetch)

    const res = await fetch(
  'https://unixcalculator.com/api/v1/convert?ts=1733529600'
);
const data = await res.json();
console.log(data.utc.iso_8601);
// "2024-12-07T04:00:00.000Z"

    Python (requests)

    import requests
r = requests.get(
    'https://unixcalculator.com/api/v1/convert',
    params={'ts': 1733529600, 'tz': 'America/New_York'}
)
data = r.json()
print(data['utc']['iso_8601'])

    Shell (curl)

    curl "https://unixcalculator.com/api/v1/convert?ts=$(date +%s)"
# Current time as JSON

    Rate limits

    100

    requests/hour

    429

    status when exceeded

    Free

    no API key needed

    Rate limit headers on every response: X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset

    Example full JSON response

    Shape for format omitted or full. Optional fields documented inline.

    {
  "input": {
    "raw": 1733529600,
    "detected_format": "seconds",
    "timezone": "America/New_York"
  },
  "unix": {
    "seconds": 1733529600,
    "milliseconds": 1733529600000,
    "microseconds": 1733529600000000
  },
  "utc": {
    "iso_8601": "2024-12-07T04:00:00.000Z",
    "rfc_2822": "Sat, 07 Dec 2024 04:00:00 GMT",
    "human": "Saturday, December 7, 2024 at 04:00:00 AM GMT",
    "date": "2024-12-07",
    "time": "04:00:00.000"
  },
  // "local" is only present when tz is not UTC — timezone-aware strings
  "local": {
    "timezone": "America/New_York",
    "formatted": "…",
    "date": "…",
    "time": "…"
  },
  "relative": {
    "human": "3 months ago",
    "is_past": true,
    "diff_seconds": 8640000
  },
  "meta": {
    "day_of_week": "Friday",
    "day_of_year": 342,
    "week_number": 49,
    "is_leap_year": true,
    "unix_y2038_safe": true
  },
  // Omitted when there are no issues
  "warnings": [
    "Timestamp exceeds Y2038 limit — check 32-bit integer fields"
  ],
  "powered_by": "unixcalculator.com",
  "docs": "https://unixcalculator.com/tools/timestamp-api"
}