Timestamp Converter — Unix, ISO 8601, Snowflake, ObjectId & More
Convert between every common time format: Unix epoch (s/ms/μs/ns), ISO 8601, RFC 2822, .NET Ticks, Windows FILETIME, Excel serial, Mac NSDate, GPS time, Julian Date, MongoDB ObjectId, UUID v1/v7 and Twitter / Discord snowflakes. Convert across any IANA time zone, add or subtract durations, batch-convert pasted lists, and inspect ISO week, quarter, day-of-year and DST. 100% client-side.
Unix epoch
Standard text formats
Office & legacy
Microsoft / Apple
Astronomy / GPS
Database / IDs
The same instant in major IANA zones. Add a custom zone in the input above.
Paste one timestamp per line. Mixed formats are fine — each line is auto-detected.
Parse or build an ISO 8601 duration like P1Y2M10DT4H30M5S.
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PT0S
All the ways this converter works
Everything happens in your browser. The same internal moment-in-time is the source of truth: every output, time-zone view and arithmetic result is recomputed from it whenever you paste a value, click Now or change a field.
All four common precisions. Auto-detected by digit count.
Canonical UTC with Z, with explicit offset, or in any IANA zone.
The format used by email headers and HTTP Date: headers.
100-ns intervals since 0001-01-01 — the .NET DateTime tick.
100-ns intervals since 1601-01-01. Same convention as Active Directory and LDAP.
Microseconds since 1601-01-01 — used in Chromium history / cookies.
Days since 1899-12-30, including the famous 1900-leap-year bug.
Seconds since 1904-01-01 UTC — the format used in classic Mac filesystems.
Seconds since 2001-01-01 — what iOS / macOS apps store internally.
Seconds since 1980-01-06; no leap seconds (currently 18 sec ahead of UTC).
The astronomical continuous day count since 4713 BC plus its modified variant.
The 32-bit packed date+time used in ZIP archives and the FAT filesystem.
First 8 hex chars = creation time in seconds. Decoded automatically.
v1 packs 100-ns ticks since 1582; v7 packs ms since 1970 in the first 48 bits.
Decoded with the 2010-11-04 epoch — gets you the exact tweet creation ms.
Decoded with the 2015-01-01 epoch — works for messages, users and channels.
Decoded with the 2011-08-24 epoch — same shift-and-add scheme.
The same instant rendered in 18 popular IANA zones, and any zone you type.
Add or subtract years, months, weeks, days, hours, minutes, seconds, ms.
Get the precise gap between two instants — total seconds, days, broken-down components and ISO 8601 duration.
Paste one per line. Each row is auto-detected and rendered in every format.
Parse a duration string into components, or build one from numeric inputs.
ISO week, day-of-year, quarter, weekday, leap-year flag, DST status, week number.
The instant is encoded in the page hash — bookmark or share the link to restore it.
A short tour of every format
1970-01-01T00:00:00Z, ignoring leap seconds. Universally portable, but ambiguous between sec/ms/μs/ns until you commit to a precision.Z or ±HH:MM) — naked local time is a bug magnet.Fri, 25 Apr 2025 14:30:00 +0000 — used by SMTP and many older log formats.DateTime.Ticks in C#. 18-digit number.Who this is for
Decode an ObjectId, snowflake or row's created_at without a SQL query.
Sanity-check millisecond vs nanosecond columns and Excel serials.
Translate a log line's epoch into your local zone and back instantly.
Convert NSDate / CFAbsoluteTime values from a crash report.
Decode a FILETIME from the registry or a SQL Server ticks column.
Convert Julian / Modified Julian / GPS time for paper appendices.
ZIP DOS time, NTFS FILETIME, Cocoa, Webkit — all in one paste-target.
See exactly how every epoch and tick rate relates to the others.
Frequently asked questions
What is a Unix timestamp?
An integer counting seconds since 1970-01-01 00:00:00 UTC, ignoring leap seconds. The same instant can be expressed in milliseconds, microseconds, or nanoseconds — common in JavaScript, Python (time.time_ns()), and high-resolution logs respectively.
How do I tell whether a number is in seconds or milliseconds?
By the digit count. As of the 2020s a 10-digit integer is seconds, 13 digits is milliseconds, 16 is microseconds and 19 is nanoseconds. The auto-detector uses this rule.
What is ISO 8601?
An international standard for date/time strings — for example 2025-04-25T14:30:00Z. It is unambiguous, sortable as plain text, and supported by every modern language. RFC 3339 is a stricter Internet profile of ISO 8601.
How do I decode a MongoDB ObjectId?
Take the first 8 hex characters of the 24-character ObjectId — that's the Unix creation timestamp in seconds. The auto-detect parser does this for you.
How do I decode a Twitter or Discord snowflake?
Snowflakes are 64-bit integers whose top 41 bits are milliseconds since a service epoch. Right-shift by 22 and add the epoch — Twitter is 1288834974657 ms, Discord 1420070400000 ms, Instagram 1314220021721 ms.
What is the Y2K38 problem?
Systems that store the Unix timestamp in a signed 32-bit integer overflow at 03:14:07 UTC on 19 January 2038. After that point the integer wraps negative. Modern OSes use 64-bit, but legacy databases, file formats and embedded code still need migration.
Why does GPS time differ from UTC?
GPS time has no leap seconds. As of 2025 it's 18 seconds ahead of UTC. The tool subtracts a constant offset only — for leap-second-accurate scientific work, use a dedicated time-scale library.
Does this tool send my data anywhere?
No. All conversions, batch parsing and time-zone formatting happen in your browser using JavaScript and the built-in Intl API. Nothing is uploaded.
Can I share a specific instant via URL?
Yes — the page hash updates to #t=<ms> as you change the moment, so the link always restores the same view.