Log Timestamp Converter

Convert epoch/ISO timestamps to KST, UTC and local time.

Timestamps buried in server logs, databases and API payloads come in all shapes: Unix epoch seconds like1718000000, milliseconds like 1718000000000, and ISO 8601 strings like2024-06-10T03:33:20Z. This log timestamp converter auto-detects the format by length and shape, then converts it to UTC, KST (Korea time), your browser's local time, plus epoch seconds and milliseconds all at once.

Use it during incident response to line up log times across systems, to turn a KST event time into a UTC epoch, or to quickly read how long ago a log line happened as a relative time. Everything is computed in your browser and nothing is sent to any server.

Timestamp

Enter epoch seconds (10 digits), milliseconds (13 digits), or an ISO 8601 string.

Auto-detection rules

The input is classified in this priority order.

10-digit number: parsed as Unix epoch seconds (e.g. 1718000000).
13-digit number: parsed as Unix epoch milliseconds (e.g. 1718000000000).
Anything else: treated as a date string (ISO 8601 etc.) and parsed with Date.

If you enter digits whose length is not 10 or 13 (say 11–12), it estimates the nearest unit and falls back to seconds when ambiguous. The now button fills in the current time instantly.

Time-zone outputs

UTC ISO: Coordinated Universal Time like 2024-06-10T03:33:20.000Z — the de-facto standard for stored logs.
KST: a fixed UTC+9 offset. Korea has no daylight saving, so it is always +9 hours.
Browser local: rendered in this device's current time-zone setting.

Reading relative time

The reference point is the current moment. Past times show as 3 minutes ago, future ones asin 2 hours. It is handy for sensing whether a log was written just now or days ago. For precise analysis, always cross-check the epoch values. To know when a batch or backup job runs next, pair it with the cron next-run calculator.

Frequently asked questions

How do you tell epoch seconds from milliseconds?

By digit count. 10 digits is treated as seconds, 13 digits as milliseconds. As of the 2020s, epoch seconds are 10 digits and milliseconds are 13.

Does KST observe daylight saving time?

No. South Korea does not currently observe daylight saving, so KST is always UTC+9 year-round. This tool uses a fixed +9 offset.

Are date formats other than ISO 8601 supported?

Most formats the browser's Date parser recognizes will work. Non-standard formats can differ between browsers, so prefer ISO 8601 (ending in Z or +09:00) when possible.

Is the time I enter sent anywhere?

No. All conversion happens in your browser and no data is transmitted to any server.

What happens when parsing fails?

An unrecognized value shows a red danger card describing the error. Check for stray spaces, quotes, or an unexpected digit count.