About Epoch Converter
Convert Unix timestamps to human-readable dates and back, with automatic detection of seconds, milliseconds, microseconds, or nanoseconds based on magnitude. See ISO 8601, RFC 2822, relative ("3 hours ago"), and three pinned timezones simultaneously. One click copies any format.
Why epoch time exists
Computers count time most easily as a single integer that always grows. Calendar time — months of varying length, leap years, leap seconds, timezones — is human-facing. The Unix epoch (00:00:00 UTC, 1 January 1970) was picked when Unix was new, and the count has been the canonical timestamp for every Unix-derived OS, every database CURRENT_TIMESTAMP under the hood, every distributed log. It is the lowest common denominator for “when”.
Units and when each appears
| Unit | Magnitude (today) | Seen in |
|---|---|---|
| seconds | ~1.7 × 10⁹ | Unix date +%s, JWT exp, classic API responses |
| milliseconds | ~1.7 × 10¹² | JavaScript Date.now(), MongoDB ObjectIds, most JSON APIs |
| microseconds | ~1.7 × 10¹⁵ | Python time.time_ns() // 1000, observability tooling |
| nanoseconds | ~1.7 × 10¹⁸ | Go time.Now().UnixNano(), Kubernetes events |
The auto-detector picks the unit by magnitude. If you paste an ambiguous value, switch the unit dropdown and watch the date update.
Common workflows
Debug a JWT expiry. Copy the exp claim from the JWT Decoder, paste here. Compare against your wall clock. Almost every “token expired” bug is clock skew.
Triage a timestamp from a log. Logs rarely tell you the unit. Paste, let auto-detect decide, eyeball the year. If it lands in 2286, the unit was wrong.
Coordinate a release across teams. Pin US-East, UTC, and your own timezone. Pick a wall-clock target in any zone — see the others update. Save you from “wait, is that PT or ET?” Slack threads.
Why a four-zone view beats one
Most converters give you UTC and your local zone. That is fine until you coordinate with a team in another region. Pinning four zones (UTC, your zone, two named teammates’) and watching them update together collapses the cognitive load — you stop converting in your head, you read.
Frequently asked questions
How does auto-detection work?
1700000000 is plausibly seconds (year 2023). 1700000000000 is the same instant in milliseconds. We pick the unit that lands in a sane year (1970-2100) and show all four interpretations if ambiguous.What is the Unix epoch?
When do timestamps overflow?
int32 will wrap. 64-bit systems are fine for the next 290 billion years.How do I get the current timestamp?
Date.now() returns ms; Math.floor(Date.now() / 1000) for seconds; Python time.time() returns seconds with float fraction; Go time.Now().Unix() seconds.Why does my timestamp show as a year 2286 date?
10_000_000_000 seconds is the year 2286, but 10_000_000_000 milliseconds is 2286 / 1000 → year 2286 / 1000 ≈ 1970 + 0.3. Use the auto-detect mode to fix it instantly.Are leap seconds handled?
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Last updated: 2025-01-15