Unix Timestamp Converter & Calculator
Turn epoch timestamps into readable dates in your local timezone, convert any date string or picked time back to a timestamp — and shift either by milliseconds, hours, days, even months and years. Everything runs locally.
Timestamp to time
Time to timestamp
Times without an explicit timezone are interpreted in your local zone — . The text field takes priority when it contains a valid date.
Unix timestamp to human-readable time
Paste any epoch value and read it as a real date in your own timezone — the tool shows your zone name, UTC offset, plus ISO 8601 and UTC formats for copy-pasting. It auto-detects whether you typed seconds or milliseconds (values ≥ 100 billion are treated as milliseconds), so logs from different systems just work.
Time to Unix timestamp
Type a date string — 2026-09-17 14:30, ISO format, or even “Sep 17 2026 2:30 PM” — or fill in the built-in year / month / day / hour / minute / second picker. Naive times (no timezone suffix) are converted using your local timezone; strings ending in Z or carrying a +08:00-style offset are honored exactly as written. You get both the classic 10-digit second timestamp and its millisecond form.
Built-in shift calculator
Both directions include a “Shift by” control: add or subtract any amount — milliseconds, seconds, minutes, hours, days or weeks use precise arithmetic; months and years are calendar-aware (January 31 + 1 month lands on February 28/29). Handy for expiry times, cron debugging, “what was the epoch 30 days ago?” questions and test fixtures.
Frequently asked questions
Why does the same timestamp show a different time for me?
A Unix timestamp is an absolute instant; only the display depends on your timezone. This tool always renders in the viewer's local zone, which is why it matches what your OS clock shows.
Seconds or milliseconds — how does auto-detect decide?
If the number is ≥ 100,000,000,000 (one hundred billion) it's treated as milliseconds; anything smaller is seconds. That covers every real-world millisecond timestamp since 1973 and every second-based one up to the year 5138 — you can still override with the Unit selector.
What does “calendar-aware” mean for months and years?
Adding a month moves you to the same day of the next month (clamped at month end), instead of adding a fixed 30/31 days — so “+1 year from Feb 29” behaves like humans expect.
Is anything uploaded?
No. All conversion happens in your browser with standard date math; the page works offline once loaded.