A timestamp decoder converts machine-readable timestamps into every human-readable format simultaneously. Whether you're debugging a log file with a Unix epoch, reading an API response with ISO 8601, or trying to understand what 1712345678 means in your local time — this tool decodes it all at once.
Enter Timestamp or Date
All Representations
Timezone Conversions
How to Use the Timestamp Decoder
Timestamps appear in logs, database records, API responses, and JWT tokens in dozens of formats. The timestamp decoder accepts any of these formats and instantly converts to all representations at once — saving the mental math of working out what 1712345678 actually means.
Step 1: Enter Any Timestamp Format
The decoder accepts multiple input formats automatically. Paste a Unix timestamp in seconds (1712345678), milliseconds (1712345678000), an ISO 8601 string (2025-04-05T12:34:56Z), or an RFC 2822 date (Sat, 05 Apr 2025 12:34:56 +0000). Click "Now" to decode the current moment.
Step 2: Read All Representations
The decoder simultaneously shows Unix seconds, Unix milliseconds, ISO 8601 in UTC and local time, RFC 2822, a human-readable string, relative time ("3 days ago"), day of year, ISO week number, and quarter. Each row has a copy button for quick access during debugging sessions.
Step 3: Check Timezone Conversions
The timezone table shows the same moment in 10 common timezones: UTC, EST (Eastern), PST (Pacific), CET (Central European), IST (India Standard), JST (Japan), AEST (Australia Eastern), BRT (Brazil), and your local timezone. This is useful when scheduling calls across regions or debugging time-based behavior in distributed systems.
Understanding Unix Epoch
The Unix epoch started at 00:00:00 UTC on January 1, 1970. Every second since then increments the Unix timestamp by 1. This timestamp reached 1 billion (10 digits) on September 9, 2001, and will reach 2 billion around May 18, 2033. Systems that store timestamps as 32-bit integers will overflow in 2038 — the "Year 2038 Problem" — which is why modern systems use 64-bit integers or milliseconds.
FAQ
What is a Unix timestamp?
A Unix timestamp (also called epoch time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC. It's the standard way to store and transmit time in computing systems because it's timezone-independent, always increases, and requires no parsing.
Is this timestamp decoder free?
Yes, this timestamp decoder is completely free. Paste any timestamp or date and instantly see the decoded output in all formats — no signup or registration required.
Is my data safe?
Yes, all decoding happens entirely in your browser. No data is sent to any server. The tool works 100% client-side.
How do I detect if a timestamp is in seconds or milliseconds?
Unix timestamps in seconds are typically 10 digits (e.g., 1712345678). Timestamps in milliseconds are 13 digits (e.g., 1712345678000). The decoder auto-detects the precision by length: 10 or fewer digits = seconds, 11-13 digits = milliseconds.
What is ISO 8601 format?
ISO 8601 is the international standard for date and time representation. The format is YYYY-MM-DDTHH:mm:ssZ (e.g., 2025-04-05T12:34:56Z). The 'T' separates date from time, and 'Z' means UTC. It's the most portable format for APIs and databases.
What is the difference between UTC and GMT?
UTC (Coordinated Universal Time) and GMT (Greenwich Mean Time) are for practical purposes identical and both at offset +00:00. UTC is the modern standard used in computing. GMT is technically an older astronomical term. Most developers use UTC when they mean the zero-offset reference timezone.
Can I decode a negative Unix timestamp?
Yes — negative Unix timestamps represent dates before January 1, 1970. For example, -86400 is December 31, 1969, 00:00:00 UTC. This decoder handles negative timestamps correctly.