Converter

Date-time converter

Convert ISO, Unix, Excel serial dates, and Mongo ObjectID timestamps with IANA timezones.

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Input

Result

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Using this tool

Inspect one instant as Unix, ISO, Excel and ObjectID timestamps, with a zoned display.

Actions: Convert

Example

Choose Unix seconds and UTC: zero is the Unix epoch. Full English-interface output is shown.

Example action and settings

Action: Convert
Input format: Unix seconds
Display timezone: UTC

Input / action

Result / expected behavior

Zoned time (UTC): Thursday, 1 January 1970 at 00:00:00 UTC
ISO 8601 / RFC 3339: 1970-01-01T00:00:00.000Z
ISO 9075 (UTC): 1970-01-01 00:00:00
RFC 7231 / UTC: Thu, 01 Jan 1970 00:00:00 GMT
Unix (s): 0
Unix (ms): 0
Excel (1900): 25569
Mongo ObjectID (timestamp example, not a unique ID): 000000000000000000000000

Available options: Input format · Display timezone

Scope and limitations

The ObjectID output is a zero-padded timestamp example, not a unique ID.
Excel 1900 serial 60, including that day’s fractional values, is rejected because the date never existed.

Common mistakes

Seconds and milliseconds differ by 1,000; select the known unit instead of relying on auto-detection.

Related tools

Integer base converter

Privacy and browser support

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