Date Format Converter
Enter a date in any common format, get it back in every common format at once.
How date format conversion works
The input date string is first parsed into an internal date value, using your format hint to resolve any genuine ambiguity — a date like 03/04/2026 could mean 3 April or 4 March depending on convention, and only a hint (or an unambiguous segment, like a day value over 12) can settle which one you meant. Once parsed, that single date is rendered out into every common format simultaneously: DD/MM/YYYY, MM/DD/YYYY, ISO 8601, DD-MMM-YYYY, RFC 2822, Unix timestamp, ordinal, and long form.
This is particularly useful when moving data between systems that expect different date conventions — spotting at a glance what a given date looks like in ISO 8601 versus a Unix timestamp, for example. For dedicated bidirectional Unix timestamp conversion with timezone support, see the Unix Timestamp Converter, and to calculate the difference between two dates rather than reformat a single one, see the Date Difference Calculator.
Frequently asked questions
- What date formats are supported as input?
- ISO 8601 (YYYY-MM-DD), slash or dash-separated numeric dates (DD/MM/YYYY or MM/DD/YYYY), DD-MMM-YYYY (e.g. 25-Dec-2026), Unix timestamps (10 or 13 digits), and most long-form or RFC 2822 strings that JavaScript's native date parser recognises.
- How is an ambiguous date like 03/04/2026 handled?
- If one segment is greater than 12 it must be the day, so it's used to disambiguate automatically. If it's genuinely ambiguous (both segments ≤12), set the format hint to DD/MM/YYYY or MM/DD/YYYY explicitly — otherwise it defaults to MM/DD/YYYY.
- What timezone are the output formats in?
- All outputs are calendar-date based (no time-of-day), computed at UTC midnight for the parsed date.
- What is ISO 8601?
- ISO 8601 is the international standard for representing dates and times, formatted as YYYY-MM-DD for dates (e.g. 2026-01-01). It sorts correctly as plain text, has no ambiguity about day/month order, and is the format recommended for data storage and interchange across nearly all modern software.
- Why is ISO 8601 the international standard?
- Its year-month-day ordering with fixed-width, zero-padded fields makes dates unambiguous regardless of locale, and sorts correctly alphabetically without any special date-aware logic — properties that regional formats like DD/MM/YYYY or MM/DD/YYYY don't share, since both are ambiguous to a reader who doesn't know which convention was used.
- What is the difference between ISO 8601 and RFC 2822?
- ISO 8601 (e.g. 2026-01-01T00:00:00Z) is optimised for unambiguous machine parsing and sorting. RFC 2822 (e.g. "Thu, 01 Jan 2026 00:00:00 +0000") is the format used in email headers and some web standards, more verbose and human-readable but less common as a general-purpose data format today.
- What is a Unix timestamp?
- A Unix timestamp is the number of seconds elapsed since 1 January 1970 UTC — a single integer representing a point in time, independent of any calendar or timezone. See the Unix Timestamp Converter for dedicated bidirectional conversion.
- Which date format should I use in software?
- Use ISO 8601 for storage, APIs, logs, and anywhere dates need to be compared or sorted programmatically. Reserve locale-specific formats (like DD/MM/YYYY) purely for display to end users, formatted according to their locale rather than hard-coded.