Timestamp Converter
Convert between Unix timestamps and human-readable dates. Live clock with ISO 8601 and relative time.
Convert between Unix epoch timestamps (seconds or milliseconds) and ISO 8601 / UTC / local dates.
Unix (seconds)
1775001600
Unix (milliseconds)
1775001600000
ISO 8601
2026-04-01T00:00:00.000Z
UTC String
Wed, 01 Apr 2026 00:00:00 GMT
Local Time
2026-04-01 00:00:00 UTC
Relative
Deterministic Epoch Reference
Day of Week
Wednesday
Day of Year
91
Week of Year
14
How do I use Timestamp Converter?
Select 'Current Time', 'Unix → Date', or 'Date → Unix', or click 'Load Sample Data' to inspect a sample epoch.
Enter a Unix timestamp (in seconds or milliseconds) or an ISO 8601 date string and click 'Convert'.
Copy any of the 9 synchronized representations (Unix sec, Unix ms, ISO 8601, UTC, Local Time, Relative, Day/Week of Year).
What features does Timestamp Converter offer?
Convert Unix epoch timestamps to human-readable dates
Live ticking Unix epoch clock display
Support for seconds and milliseconds timestamps
100% client-side privacy guarantee
POSIX Unix Epoch Time, ISO 8601 Formatting & The Year 2038 Problem
Unix time counts the number of non-leap seconds elapsed since `1970-01-01T00:00:00Z` (UTC). JavaScript `Date.now()` uses milliseconds (13 digits), whereas POSIX systems, JWT `exp` claims, and Python `time.time()` use seconds (10 digits).
| Timestamp Format | Digit Length | Example Value | Architecture / Overflow Limit |
|---|---|---|---|
| Unix Seconds (POSIX) | 10 digits | 1775001600 | 32-bit signed int overflows on 2038-01-19T03:14:07Z |
| Unix Milliseconds (JS) | 13 digits | 1775001600000 | JavaScript Date max range is ±8.64e15 ms (±273,785 years) |
| ISO 8601 UTC | 20–24 chars | 2026-04-01T00:00:00.000Z | Trailing 'Z' denotes Zero UTC offset |
| RFC 2822 / HTTP Date | 29 chars | Wed, 01 Apr 2026 00:00:00 GMT | Used in HTTP Last-Modified, Expires & Set-Cookie headers |
Frequently Asked Questions about Timestamp Converter
How does the converter automatically distinguish Unix seconds from milliseconds?
Any integer greater than `10,000,000,000,000` (10 trillion, or 13+ digits for modern dates) is parsed as milliseconds since the 1970 epoch, while 10-digit values under that threshold are multiplied by 1,000 and treated as POSIX seconds.
What is the Year 2038 (Y2K38) problem in Unix timestamps?
Legacy systems that store Unix timestamps as a signed 32-bit integer (`INT32_MAX = 2,147,483,647`) will overflow to a negative number on January 19, 2038 at `03:14:07 UTC`. Always store timestamps in 64-bit integers (`BIGINT`) or `TIMESTAMPTZ`.
Are Unix timestamps affected by local timezones or Daylight Saving Time (DST)?
No. A Unix timestamp is always anchored to UTC (`1970-01-01T00:00:00Z`) and is identical simultaneously everywhere on Earth. Timezone offsets (`+07:00`, `America/New_York`) are only applied when formatting the timestamp into a human-readable local string.
Do Unix timestamps count leap seconds?
No. POSIX time defines every day as exactly 86,400 seconds, ignoring leap seconds so arithmetic intervals (`timestamp + 86400`) remain deterministic.
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