Converter
Pick one date and see it rendered in every format you're likely to need — no more guessing whether 03/04 means March 4th or April 3rd.
Using a date picker instead of free text on purpose — it's the only way to guarantee the input itself is never ambiguous.
There's no single global convention for writing dates. The US defaults to month-day-year, most of Europe and the rest of the world defaults to day-month-year, and ISO 8601 exists specifically to sidestep the disagreement with an unambiguous year-first format. RFC 2822 is what email headers and some HTTP contexts expect. None of these are wrong — they're just different audiences.
If you're formatting dates in code rather than by hand, the Epoch Time in Programming Languages guide has the actual function calls for each language. For a deeper look at why the ambiguity causes real bugs, see the blog.
Related
Why this specific format sorts and parses better than the rest.
Convert into Excel serials, .NET ticks, GPS time, and more.
Go from a Unix timestamp straight to any of these formats.