⏰ Epoch / Unix Timestamp Converter
Convert Unix timestamps to human dates and back - seconds and milliseconds supported
Mon, 06 Apr 2026 06:25:34 GMT2026-04-06T06:25:34.000Z4/6/2026, 6:25:34 AMjust now17754567340001775456734How to Use the Epoch Converter
Unix timestamps count seconds (or milliseconds) since January 1, 1970 UTC - the Unix Epoch. This tool converts between timestamps and human-readable dates instantly. Use it when debugging API responses, database records, log files, or JWT expiry times.
Input
1700000000UTC Output
Thu, 14 Nov 2023 22:13:20 GMTThe tool auto-detects whether your input is in seconds (10 digits) or milliseconds (13 digits). Click Now to get the current timestamp. Switch to Date → Timestamp to convert any date into its Unix equivalent - useful for building API queries with date filters.
Why does JavaScript use milliseconds instead of seconds for timestamps?
JavaScript's Date.now() returns milliseconds since the Unix epoch — a design choice for animation and UI precision. The downside is constant confusion when interfacing with Unix system timestamps (seconds), database TIMESTAMP columns (seconds), or REST APIs (usually seconds). The quick rule: 10-digit timestamp = seconds. 13-digit timestamp = milliseconds. If you divide a 13-digit value by 1000, you get the seconds version. Forgetting this conversion when constructing a JavaScript Date from a server timestamp is one of the most common datetime bugs in web development.
What is the difference between this Epoch Converter and the Unix Timestamp tool?
Both convert timestamps to human-readable dates, but differently. The Unix Timestamp tool handles seconds-precision from system logs and databases — clean and simple. The Epoch Converter adds millisecond precision, shows UTC and local time side by side, and outputs ISO 8601 format. Use Unix Timestamp for Linux log files and PostgreSQL timestamps. Use this Epoch Converter when debugging JavaScript applications where Date.now() is your primary timestamp source.
What is ISO 8601 and why is it the standard for APIs?
ISO 8601 represents dates as 2026-04-15T14:30:00.000Z. The T separates date and time; Z means UTC. Advantages: unambiguous (unlike 04/05/2026), sorts correctly as a string, includes timezone info, and is human-readable. JavaScript's JSON.stringify() automatically serializes Date objects to ISO 8601. When designing an API, always output ISO 8601 — it is the universal API date format.
How do I convert between a JavaScript Date and a Unix timestamp?
Date to seconds: Math.floor(Date.now() / 1000). Date to milliseconds: Date.now(). Seconds to Date: new Date(timestamp * 1000) — the *1000 is critical. Milliseconds to Date: new Date(timestampMs). The most common bug: forgetting *1000 when constructing Date from a seconds value, making JavaScript interpret 1,700,000,000 as milliseconds and producing a date in January 1970.
What does Z mean at the end of an ISO 8601 timestamp?
Z stands for Zulu time — NATO phonetic alphabet for zero UTC offset. 2026-04-15T14:30:00Z is exactly 14:30 UTC. A timestamp with +05:30 offset is in IST (India Standard Time). Always store timestamps as UTC (Z suffix) and convert to local time only for display. Storing in local time causes bugs during DST transitions and makes timezone-aware database queries unreliable.
How do I measure JavaScript execution time accurately?
Use performance.now() rather than Date.now() for measuring code duration — it has sub-millisecond precision and is unaffected by system clock adjustments. const start = performance.now(); heavyOperation(); const ms = performance.now() - start. Use Date.now() for absolute timestamps (recording when something happened). For Node.js, process.hrtime.bigint() provides nanosecond precision.
What other time and date tools are on this site?
The Unix Timestamp tool handles seconds-precision system timestamps. The Timezone Converter shows one UTC time in multiple local zones simultaneously — ideal for scheduling across regions. The Cron Expression Generator builds scheduled task schedules and previews the next 5 execution times. The JSON Formatter helps extract timestamp fields from API responses. All are in the Dev Tools section.
📊 Key Data Points
1970-01-01
Unix epoch origin — all Unix timestamps are seconds (or ms) since this UTC moment
2038 problem
32-bit Unix timestamps overflow on 19 Jan 2038 — 64-bit timestamps avoid this
13 digits
Millisecond timestamps have 13 digits; second timestamps have 10 — auto-detected
Epoch Converter — Unix Timestamp -- Complete USA Guide 2026
Unix epoch timestamps appear everywhere in software: database columns, API responses, JWT tokens, log files, and event tracking. But raw timestamps like 1735689600 or 1735689600000 are meaningless to humans — you cannot tell whether it is in the past or future without converting.
This converter handles both second-precision and millisecond-precision timestamps, converts to local time in any timezone. Runs in your browser.
**Long-tail searches answered here:** convert unix milliseconds timestamp to human readable date, what date is epoch timestamp 1735689600, current unix timestamp in milliseconds online.
For more timestamp operations, see Unix Timestamp and Timezone Converter.
🔬 How This Calculator Works
Uses JavaScript Date object to convert between Unix timestamps and human-readable dates. Auto-detects seconds vs milliseconds: values greater than 9,999,999,999 are treated as milliseconds.
Date-to-timestamp converts using Date.prototype.getTime() / 1000 (seconds) or Date.prototype.getTime() (milliseconds). The current timestamp updates live every second using Date.now().
All conversions respect your browser local timezone for display, while also showing the UTC equivalent.
✅ What You Can Calculate
Auto-detects seconds vs milliseconds
Automatically distinguishes between 10-digit second timestamps and 13-digit millisecond timestamps — no need to divide by 1000 manually before pasting.
Current timestamp live display
Shows the current Unix timestamp updating in real time — instantly copy the current second or millisecond value for use in API calls or database queries.
Date to timestamp conversion
Enter a human-readable date and get the Unix timestamp back — useful for building date range queries with WHERE created_at > 1735689600.
Relative time display
Shows how long ago or until a timestamp — 3 days ago, in 2 hours. Makes it immediately clear whether a timestamp refers to a past event or a future one.
🎯 Real Scenarios & Use Cases
Debugging JWT expiry
Your JWT token has an exp field with a timestamp value. Paste here to see whether the token has expired or is still valid — without writing a Node.js script.
Database timestamp queries
You need to query rows created after a specific date. Convert your target date to a Unix timestamp here and paste it directly into your WHERE clause.
Log file timestamp parsing
Application logs often use Unix timestamps. Convert individual log timestamps here to understand when events occurred relative to each other.
API response timestamp reading
API responses return created_at and updated_at as Unix timestamps. Convert them here to see whether your cache invalidation window is correctly set.
💡 Pro Tips for Accurate Results
Check your JWT exp field. Use JWT Decoder to extract the exp value, then paste it here to see the exact expiry time.
10 digits = seconds, 13 digits = milliseconds. When in doubt, check the digit count before dividing by 1000.
Milliseconds for high-frequency events. Log systems, metrics, and event tracking typically use millisecond timestamps.
Database NOW(). PostgreSQL EXTRACT(EPOCH FROM NOW()) and MySQL UNIX_TIMESTAMP() return second-precision. For milliseconds in PostgreSQL, use (EXTRACT(EPOCH FROM NOW()) * 1000)::BIGINT.
🔗 Use These Together
🏁 Bottom Line
Unix timestamps appear in virtually every layer of a web application — databases, APIs, tokens, logs, and analytics. Being able to convert them instantly without opening a Node.js REPL saves time daily.
For the full time-handling toolkit: convert timestamps here, decode JWT time fields with JWT Decoder, and plan scheduled tasks with Cron Expression Builder.