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Timestamp Converter

Convert between Unix timestamps, DateTime strings, and ISO 8601 formats with timezone support. Essential for developers, database administrators, and system integration.

Current Time

Local Time

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UTC Time

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Unix Timestamp

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ISO 8601

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Examples: 1735400000, "2024-12-28 12:00:00", "2024-12-28T12:00:00Z"
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Seconds since Jan 01 1970 (UTC)
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Milliseconds since Jan 01 1970 (UTC)
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International standard date/time format
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Localized date and time format
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Standard for email headers (HTTP dates)
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Format tokens: YYYY=year, MM=month, DD=day, HH=24-hour, hh=12-hour, mm=minute, ss=second

Timestamp Formats Explained

Unix Timestamp (Epoch Time)

A Unix timestamp (also called Epoch time) represents the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC (Coordinated Universal Time), not counting leap seconds. This is a simple integer that is timezone-agnostic and easy to store and compare.

Key Characteristics:

  • Seconds since Jan 1, 1970 00:00:00 UTC
  • 32-bit signed integer (until 2038 problem)
  • 64-bit timestamps also common
  • Millisecond precision often used

Common Uses:

  • Database timestamps
  • File system timestamps
  • API response times
  • Log file entries
  • Caching timestamps

Example: 1735401600 = December 28, 2024 12:00:00 UTC

Milliseconds: 1735401600000 (append 000)

ISO 8601 International Standard

ISO 8601 is an international standard for date and time representations. It provides unambiguous, human-readable, and sortable date/time strings. The format is widely used in computing, data interchange, and APIs.

Common Formats:

  • YYYY-MM-DDTHH:mm:ssZ (UTC)
  • YYYY-MM-DDTHH:mm:ss±HH:mm (with offset)
  • YYYY-MM-DD (date only)
  • HH:mm:ss (time only)

Advantages:

  • Human readable
  • Lexicographically sortable
  • Time zone aware
  • International standard
  • Machine parseable

Examples:

2024-12-28T12:00:00Z (UTC)

2024-12-28T13:00:00+01:00 (Paris time)

2024-12-28 (date only)

Human Readable Date/Time

Human readable date/time formats vary by locale and application. They're designed for human consumption rather than machine processing. Common formats include local conventions, database formats, and application-specific representations.

Common Formats:

  • YYYY-MM-DD HH:mm:ss (SQL, logs)
  • MM/DD/YYYY HH:mm:ss (US format)
  • DD/MM/YYYY HH:mm:ss (EU format)
  • Mon DD, YYYY HH:MM:SS PM
  • RFC 2822: Sat, 28 Dec 2024 12:00:00 GMT

Locale Variations:

  • US: Month/Day/Year
  • EU: Day/Month/Year
  • ISO: Year-Month-Day
  • 12-hour vs 24-hour clock
  • AM/PM indicators

Examples:

2024-12-28 12:00:00 (MySQL)

12/28/2024 12:00:00 PM (US)

28/12/2024 12:00:00 (EU)

Timezones & UTC

Timezones represent regions that observe a uniform standard time for legal, commercial, and social purposes. UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks and time. It's the successor to Greenwich Mean Time (GMT).

Key Concepts:

  • UTC: Universal reference time
  • GMT: Greenwich Mean Time (≈UTC)
  • DST: Daylight Saving Time
  • Offset: ±HH:mm from UTC
  • IANA Timezone database

Best Practices:

  • Store timestamps in UTC
  • Convert to local time for display
  • Use IANA timezone names
  • Handle DST transitions carefully
  • Include timezone in APIs

Common Timezones:

UTC - Universal Time Coordinated

EST - Eastern Standard Time (UTC-5)

CET - Central European Time (UTC+1)

The Year 2038 Problem

The Year 2038 problem (also known as Y2038 or Unix Millennium Bug) is a time computing problem that will cause some computer systems to fail in dealing with times beyond 03:14:07 UTC on 19 January 2038. This is because many systems store time as a 32-bit signed integer.

Technical Details:

  • 32-bit signed integer maximum: 2,147,483,647
  • This equals: 03:14:07, Jan 19, 2038 UTC
  • After this, timestamps wrap to negative
  • Affects older systems and embedded devices

Solutions:

  • Use 64-bit timestamps
  • Store as unsigned 32-bit integer
  • Use string-based formats
  • Update legacy systems

Critical Timestamps:

2038-01-19 03:14:07 UTC = 2147483647 (max 32-bit signed)

2038-01-19 03:14:08 UTC = -2147483648 (overflow!)

Quick Timestamp Reference

Important Epoch Times:

  • Unix Epoch Start: 0
  • Y2K (Jan 1, 2000): 946684800
  • Facebook Founded: 1072915200
  • iPhone Introduced: 1167609600
  • Today (approx): -
  • 2038 Problem: 2147483647

Format Comparison:

  • Unix (seconds): 1735401600
  • Unix (ms): 1735401600000
  • ISO 8601: 2024-12-28T12:00:00Z
  • Human Readable: Dec 28, 2024 12:00:00
  • RFC 2822: Sat, 28 Dec 2024 12:00:00 GMT
  • MySQL: 2024-12-28 12:00:00

Developer Tips

• Always store timestamps in UTC in your database

• Use ISO 8601 for API responses

• Consider 64-bit timestamps to avoid 2038 problem

• Include timezone information in all date/time data

• Use IANA timezone names (e.g., "America/New_York")