Timestamp Converter — Unix Epoch to Date & Back
Convert Unix epoch seconds, milliseconds, and date strings to ISO 8601, UTC, local time, and back — instantly in your browser
How to use this timestamp converter tool
- Watch the live clock panel for current Unix seconds, milliseconds, microseconds, and ISO 8601 — copy any value instantly.
- Choose Epoch → Date to convert a numeric timestamp or date string into readable formats.
- Choose Date → Epoch to pick a date and time and get Unix seconds and milliseconds.
- Choose Batch to paste multiple values (one per line) and export results as CSV.
- Set Unit detection to Auto (recommended) or force seconds, milliseconds, microseconds, or nanoseconds.
- Pick a display timezone — local browser, UTC, or common IANA zones like America/New_York or Asia/Tokyo.
- Use Now, ±1 hour, and quick examples to test edge cases without typing.
About this timestamp converter tool
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds that have elapsed since 1 January 1970 00:00:00 UTC — the Unix epoch. It is the standard way databases, APIs, log files, and mobile apps store a single moment without worrying about timezones or daylight saving rules.
VSPIC timestamp converter is a full developer workspace for moving between epoch numbers and readable dates. Paste a 10-digit second value, a 13-digit millisecond value, a 16-digit microsecond log entry, or an ISO 8601 date string — the tool auto-detects the format and shows every common representation at once. Pick a timezone, read relative time like “3 hours ago”, convert dates back to epoch with a visual picker, batch-convert dozens of values, and copy any row with one click.
All conversion runs locally with native JavaScript Date and Intl APIs. Your log timestamps and event data never leave your device.
Why use VSPIC for timestamp converter?
- Auto-detects seconds (10 digits), milliseconds (13), microseconds (16), and nanoseconds (19).
- Outputs Unix seconds, milliseconds, microseconds, ISO 8601, RFC 2822, UTC, and timezone-formatted dates.
- Live current-time panel updates every second with one-click copy.
- Relative time (“2 days ago”), day of week, day of year, and ISO week number.
- Visual datetime picker for date-to-epoch with ±1 hour shortcuts.
- Batch mode converts mixed inputs and downloads CSV.
- Y2038 overflow warning for timestamps beyond 32-bit signed seconds.
- 100% client-side — safe for production log samples and private event data.
What is a Unix timestamp?
A Unix timestamp counts time from the epoch: 1 January 1970 00:00:00 UTC. Ten-digit numbers are usually seconds — what you see in Linux logs, Python time.time(), and many REST APIs. Thirteen-digit numbers are usually milliseconds — what JavaScript Date.now() returns and what browser performance APIs record.
Because the number is timezone-independent, the same epoch value means the same instant everywhere. That makes timestamps ideal for sorting events, storing created_at columns, and passing time through JSON without ambiguity.
Who uses timestamp converters?
Backend developers decode API response fields and database created_at values. Front-end engineers convert between JavaScript milliseconds and server seconds. DevOps and SRE teams correlate log lines from different systems that store time in different units. QA testers verify scheduled jobs and token expiry times.
Data analysts joining CSV exports use converters to make epoch columns readable in spreadsheets. Students learning about time in programming use the live clock and examples to connect code output with calendar dates.
How to use this timestamp converter
Start with Epoch → Date if you have a number from a log or API. Leave Unit on Auto — the tool counts digits to decide seconds vs milliseconds vs microseconds. If the year looks wrong (1970 or far future), switch the unit manually: a seconds value read as milliseconds lands in 1970; milliseconds read as seconds land decades ahead.
For Date → Epoch, use the datetime picker or type an ISO string like 2024-06-15T14:30:00Z. The Z suffix means UTC. Results show both second and millisecond forms so you can paste the one your API expects.
Batch mode accepts mixed lines — seconds, milliseconds, and ISO strings together. Download CSV to paste into spreadsheets or share with your team.
Seconds vs milliseconds vs microseconds
Seconds (10 digits): Standard Unix time in C, Go, PHP time(), PostgreSQL extract(epoch), and most Linux tooling.
Milliseconds (13 digits): JavaScript Date.now(), Java System.currentTimeMillis(), MongoDB dates, and many JSON APIs.
Microseconds (16 digits): Some logging frameworks, Prometheus, and databases with sub-millisecond precision.
Nanoseconds (19 digits): High-resolution performance traces — displayed with a precision note because JavaScript dates round to milliseconds.
Version and format outputs explained
ISO 8601 (UTC): International standard format with a Z suffix — YYYY-MM-DDTHH:mm:ss.sssZ. Use this in JSON payloads and cross-system exchange.
RFC 2822: Email and HTTP header style — Wed, 15 Jun 2024 14:30:00 +0000. Useful when comparing with mail server or CDN logs.
UTC string: Browser toUTCString() output — human-readable absolute time in GMT.
Timezone row: Formatted with Intl for your chosen IANA zone — includes daylight saving when applicable.
Relative time: Distance from now in plain language — helpful for token expiry, scheduled jobs, and “how old is this log line”.
Timestamp converter vs manual calculation
Multiplying or dividing by 1000 is error-prone when tired or under pressure — one extra zero shifts the date by decades. Auto-detection and side-by-side second and millisecond outputs prevent the most common debugging mistake.
Spreadsheet DATE functions struggle with epoch seconds vs milliseconds and timezone offsets. A dedicated converter shows UTC, local, and named timezone rows together.
Compared to guessing from log format, batch mode validates dozens of values at once and flags lines that fail to parse.
Timezone and daylight saving notes
Epoch values are always absolute — timezone only affects display. Pick UTC when comparing servers in different regions. Pick a named zone when you need to know local wall-clock time for a user-facing event.
Ambiguous local times during daylight-saving “fall back” may parse differently across browsers. When precision matters, input and store ISO 8601 with an explicit Z or offset.
Y2038 and 32-bit systems
Signed 32-bit Unix seconds overflow on 19 January 2038. Systems still using 32-bit time_t may wrap or fail. This tool warns when a timestamp exceeds that boundary so you can plan migrations to 64-bit or millisecond storage early.
Privacy
Conversion uses only your browser. No timestamps are logged or transmitted. Refresh clears in-memory state unless you saved preferences locally.
Important notes & limitations
- JavaScript Date precision is milliseconds — sub-millisecond values are truncated in date display.
- Datetime picker uses your browser local timezone; UTC and ISO outputs clarify absolute time.
- Natural-language dates depend on browser parse rules — prefer ISO 8601 for unambiguous input.
- Does not replace server-side timezone logic in production apps — verify with your runtime.
- Leap seconds are not modeled separately — same behavior as standard JavaScript Date.
timestamp converter — frequently asked questions
Yes. VSPIC offers this timestamp converter at no cost with no account required. Results load in real time.
We do not permanently store your queries on our servers. Some tools run entirely in your browser; others fetch public data for the request only.
Yes. Open the page in any modern phone or tablet browser. Results work on Wi‑Fi and mobile data.
Count the digits. Ten digits is almost always seconds. Thirteen is milliseconds. Sixteen is microseconds. Leave Unit on Auto and the tool detects automatically — switch manually if your data uses a non-standard length.
You likely pasted seconds but the tool (or your code) treated them as milliseconds. A value like 1710000000 ms is only about 20 days after the epoch. Enable Force seconds or divide by 1000 before converting.
Milliseconds were probably read as seconds. 1710000000000 seconds is tens of thousands of years ahead. Use Auto detection or Force milliseconds.
Pick from the timezone dropdown — browser local, UTC, or a named IANA zone. Epoch input itself has no timezone; display adds the zone you choose.
Yes. Switch to Date → Epoch, use the datetime picker or type an ISO string, and copy Unix seconds or milliseconds from the results.
Yes. Negative Unix seconds represent dates before 1 January 1970. Try the Pre-1970 example button.
Yes. Batch mode accepts one value per line — mixed seconds, milliseconds, and ISO strings — and lets you download results as CSV.
It appears when a timestamp exceeds 2,147,483,647 Unix seconds — the limit of signed 32-bit integers. Older systems may break; plan for 64-bit time storage.
They are parsed and shown as numbers, but JavaScript Date display rounds to milliseconds. A note appears when sub-millisecond precision cannot be shown in the calendar date.
No. All conversion runs locally in your browser using JavaScript Date and Intl.
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