Date & Time Format Converter

How to Use

1. Paste or type any date string, Unix timestamp, or ISO 8601 date into the input field.
2. Or click Now to use the current date and time.
3. Select a timezone from the dropdown to see results in that region.
4. View all converted formats in the results grid below.
5. Click Copy next to any format to copy it to your clipboard.

Understanding Date Formats

Developers regularly encounter dates in different formats across APIs, databases, log files, and configuration. A timestamp in a PostgreSQL database looks different from one in a JSON API response, which looks different from a log file entry. This tool converts between all common formats instantly, saving you from manual calculations and reducing the risk of timezone-related bugs.

The most common source of date bugs is ambiguity. Does 03/10/2026 mean March 10 or October 3? In the United States, it means March 10 (MM/DD/YYYY). In most of Europe, it means October 3 (DD/MM/YYYY). ISO 8601 was created specifically to eliminate this ambiguity by using the unambiguous YYYY-MM-DD format.

ISO 8601 Explained

ISO 8601 is the international standard for date and time representation, first published in 1988 and widely adopted across the software industry. The full format is YYYY-MM-DDTHH:mm:ss.sssZ, where:

• YYYY-MM-DD is the date in year-month-day order (no ambiguity)
• T is a literal separator between date and time
• HH:mm:ss.sss is the time with optional milliseconds
• Z indicates UTC, or a +/-HH:mm offset for other timezones

ISO 8601 is the required format for JSON APIs (per RFC 8259 recommendations), JavaScript's Date.toISOString(), and most modern databases. If you are designing an API or data format, always use ISO 8601.

RFC 2822 Date Format

RFC 2822 defines the date format used in email headers and HTTP headers. It looks like Tue, 10 Mar 2026 12:00:00 +0000. While human-readable, it is more verbose than ISO 8601 and includes abbreviated day and month names in English. You will encounter this format in email Date: headers, HTTP Last-Modified headers, and RSS feeds.

Working with Unix Timestamps

Unix timestamps represent a point in time as a single number: the count of seconds since the Unix epoch (January 1, 1970, 00:00:00 UTC). This format is compact, timezone-independent, and trivially comparable. Most backend systems, databases, and programming languages support it natively.

A common pitfall is confusing seconds and milliseconds. A 10-digit number like 1741608000 is seconds. A 13-digit number like 1741608000000 is milliseconds. JavaScript's Date.now() returns milliseconds, while Python's time.time() returns seconds as a float. This tool auto-detects which you have entered.

Working with Timezones

Timezone handling is one of the most error-prone areas in software development. Key principles to remember:

• Store in UTC — always store timestamps in UTC in your database. Convert to local time only for display.
• Use timezone-aware types — prefer TIMESTAMP WITH TIME ZONE in PostgreSQL, datetime.datetime with tzinfo in Python, and ZonedDateTime in Java.
• Beware DST transitions — daylight saving time means the UTC offset for a given timezone changes twice a year. Never hardcode offsets.
• Use IANA timezone names — names like America/New_York are unambiguous and account for historical DST changes. Abbreviations like "EST" are ambiguous.

Common Pitfalls

Month/day ambiguity: Always use ISO 8601 (YYYY-MM-DD) or explicit month names to avoid MM/DD vs DD/MM confusion across locales.

Midnight edge cases: Some systems represent midnight as 24:00:00 of the previous day rather than 00:00:00 of the current day. ISO 8601 allows both.

Leap seconds: UTC occasionally adds leap seconds (23:59:60), which most programming languages and timestamps silently ignore. For most applications, this does not matter.

The Year 2038 problem: Systems storing Unix timestamps as 32-bit signed integers will overflow on January 19, 2038. Modern 64-bit systems are unaffected, but embedded systems and legacy databases may still be vulnerable.

Related Tools

Convert Unix timestamps with the Epoch / Unix Timestamp Converter. Schedule recurring tasks with the Cron Expression Generator. Decode JWT tokens containing date claims (iat, exp, nbf) with the JWT Decoder. Format JSON API responses that contain date strings with the JSON Formatter.