What Date Format Is This? Detect & Convert Online

Detect and explain date formats

Paste a date or timestamp — from a log file, a spreadsheet, or an API response — and the tool identifies the format: ISO 8601, Unix timestamp, RFC 3339, Excel serial number, and dozens more.

See the format name and how each component (year, month, day, offset) maps to the input.
Convert to other representations in the original timezone, your local timezone, or any IANA zone.
Switch to batch mode to normalize a list of mixed dates at once.

Typical use cases

Decoding a Unix timestamp or Windows Filetime value from a database dump or debug log.
Turning a numeric Excel date into something readable before dropping it into a report.
Figuring out the timezone offset in a log entry from a server in another region.
Understanding a date written in an unfamiliar locale or relative format ("вчера", "hace 2 horas").

Supported formats

Format	Masks
ISO 8601	date_time_tz, date_time_utc, date_only, compact
Unix Timestamp	seconds, milliseconds
RFC 3339	utc, offset
RFC 2822	—
ISO 9075	date, datetime
SQL DATE / DATETIME	date, datetime
Excel Serial Date	date, datetime
Windows Filetime	—
Julian Date (JD)	integer, fractional
Tire DOT Code	—
Mac Timestamp	—
Human Readable / Text Date	date, datetime
Chinese Date	date, datetime
.NET Ticks	—
Locale / human-readable date	date, datetime
US Date (month-first)	date, datetime
OLE Automation Date (VBA/COM)	date, datetime
NTP Timestamp	—
GPS Time	—
MongoDB ObjectId	—
PDF Date	local, utc_or_offset
Microsoft JSON Date (WCF)	—

Frequently asked questions

Which date formats does the service support?

The tool is a universal converter and recognizes a wide range of formats:

Standards and ISO: ISO 8601, RFC 3339 (e.g. 2026-01-06T15:08:07.237Z).
Technical: Unix timestamps (seconds and milliseconds), Microsoft Filetime (including HEX), Julian dates.
Spreadsheets: Excel serial date numbers (e.g. 45901).
Textual: Dates written in words in many languages (English, Russian, French, etc.), e.g. 12 November 2025 or janv. 01, 2005.

Can I convert relative phrases like “now” or “yesterday”?

Yes. The service understands phrases such as now (current time) and yesterday and converts them to precise ISO 8601 values.

I have a list of dates. Can I process them all at once?

Yes. Bulk conversion is supported. Paste a long list or a fragment from a log file and the system will try to detect and convert each value.

Will it work if the date is inside text or a filename?

Yes. Dates can be extracted from strings such as:

Log lines: DateTime: 2026-03-03T22:14:47…
Filenames: 12-10-2025_20-06-42 File
Technical reports: Import Start Time (UTC+0): 2025-04-28…

How do I turn Windows system time (Filetime) into a normal date?

Paste the numeric value (e.g. 1.32641938014656E+16) or the hexadecimal form (e.g. B5E27B0AE8BBD601). The service detects Microsoft Filetime and shows the corresponding date and time.

Does the service handle timezones?

Yes. It handles numeric offsets (e.g. +07:00, -05:00) and zone abbreviations such as UTC, GMT, PDT, or JST.

What happens if I enter invalid data?

If the input does not contain a recognizable date (e.g. random letters like 4qweqwer), the API returns false to indicate that conversion is not possible.

Can I see what time it is in a specific country for a given UTC value?

Yes. Many users ask things like “2026-02-28T00:03:46.750Z — what time is that in Brazil?” or want conversion to “Sydney time”. The tool helps map global time to local time.

API

Endpoint	Method	Notes
/api/v1/parse	POST	Parses a date/time string and returns possible formats and conversions.

Request (JSON)

{
  "input": "2026-03-18T12:34:56Z"
}

Response (example)

{
  "ok": true,
  "results": [
    {
      "format": "ISO 8601",
      "mask": "YYYY-MM-DDTHH:mm:ssZ",
      "representations": [
        { "label": "ISO 8601", "value": "2026-03-18T12:34:56Z" }
      ]
    }
  ]
}

Date & Time Format

Conversion to other formats

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