Timestamp Converter Guide

Quick answer

Enter a Unix timestamp, an ISO date string, or a readable date value, and the converter shows it in Unix seconds, Unix milliseconds, ISO 8601, UTC, and your local time zone simultaneously. All conversion runs in your browser.

What this tool does

The timestamp converter translates between different machine-readable and human-readable time representations. It handles Unix timestamps in both seconds and milliseconds, ISO 8601 strings, and common date formats parsed by the browser.

Supported input

• 10-digit integer → treated as Unix seconds (standard Unix timestamp)
• 13-digit integer → treated as Unix milliseconds (JavaScript Date.now() format)
• ISO 8601 string → parsed by the browser date parser, for example 2026-05-29T14:32:07Z or 2026-05-29 14:32:07+08:00
• Common date string → parsed by the browser, for example May 29 2026 or 2026-05-29

Output

For each valid input, the tool displays:

• Unix seconds (raw integer)
• Unix milliseconds (raw integer)
• ISO 8601 (UTC)
• UTC (human-readable)
• Local time (in your browser's current time zone)

Each row has a copy button.

Step-by-step use

1. Paste or type a timestamp or date into the input field
2. The conversion runs automatically as you type
3. Review the output in all five formats
4. Click the copy button next to the format you need
5. Paste the copied value into your log, ticket, documentation, or script

Practical workflow

For logs, API events, and analytics exports, start by confirming whether the value is seconds, milliseconds, or an ISO string. Anchor the interpretation in UTC first, then compare local time only after the unit is clear. If the timestamp is part of a schedule, deadline, or media timing note, use the Time Planning Workflow to connect timestamp conversion with durations, time zones, and business-day assumptions.

Data handling and processing behavior

Conversion is designed to happen in your browser using the built-in JavaScript Date object. Avoid entering sensitive timestamp values unless you have reviewed the current public implementation.

The local time output depends on your browser and system time zone settings. UTC and ISO output are stable and do not depend on the local device.

Limits

• Very unusual date strings may not parse consistently across browsers. When precision matters, use a Unix timestamp (seconds or milliseconds) or an ISO 8601 string.
• The browser date parser does not support all international date formats. If a date string fails to parse, try converting it to ISO 8601 first.
• Dates before 1970 or after approximately the year 275,760 may not convert correctly in all browsers because they exceed the range of JavaScript's internal date representation.

Practical handoff note

For timestamp handoff, include seconds versus milliseconds, timezone, source system, and converted date together. Timestamp mistakes often come from unit confusion or timezone assumptions. For logs and incidents, preserve the original raw timestamp beside the readable time.

Common errors

Input is read as the wrong unit

A 10-digit timestamp is seconds. A 13-digit timestamp is milliseconds. If your result looks like a date in 1970 or in the year 55,000, the unit is wrong. Check the digit count and adjust accordingly.

Ambiguous date strings parse differently by locale

A string like 05/06/2026 could mean May 6 or June 5 depending on whether the system locale is US or European. Always use ISO 8601 (YYYY-MM-DD) when sharing timestamp values to avoid this ambiguity.

Time zone confusion

Local time changes depending on where you are. When comparing logs from servers in different time zones, always anchor to UTC first, then convert to the relevant local time zone.

Next steps

• Time Planning Workflow — combine timestamps, durations, time zones, and deadline assumptions
• Time Duration Calculator — calculate the duration between two timestamps or dates
• Time Zone Converter — convert a specific time across IANA time zones
• Time Unit Converter — convert seconds, milliseconds, minutes, and HH:MM:SS values
• Age Calculator — calculate age and date differences from a birth date
• Date Add Calculator — add or subtract days, weeks, months, or years from a date