Timestamp Converter

How to Use the Timestamp Converter

This free online timestamp converter lets you convert between Unix timestamps and human-readable dates instantly. Enter a Unix timestamp (in seconds or milliseconds) and click Convert to see the corresponding date in both UTC and your local timezone. You can also enter a date string to get the Unix timestamp. The "Current Time" button shows the current moment in all formats. All processing is done in your browser, so nothing is transmitted to any server.

What is a Unix Timestamp?

A Unix timestamp (also known as Epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970, 00:00:00 UTC, known as the Unix Epoch. This system provides a simple, timezone-independent way to represent a specific moment in time as a single integer. Unix timestamps are used extensively in databases, APIs, log files, server configurations, and programming languages across all platforms.

Seconds vs Milliseconds

Traditional Unix timestamps are measured in seconds, producing a 10-digit number for current dates (e.g., 1711929600). However, many programming languages and APIs use millisecond precision, producing a 13-digit number (e.g., 1711929600000). JavaScript, for example, uses milliseconds natively in Date.now() and the Date constructor. This tool automatically detects whether your input is in seconds or milliseconds and converts accordingly, showing both values in the output.

Supported Date Formats

When converting from date to Unix timestamp, you can enter dates in various formats including ISO 8601 (2026-04-01T12:00:00Z), common date format (2026-04-01 12:00:00), and most formats recognized by the JavaScript Date parser. For best results, use ISO 8601 format or include the timezone offset. If no timezone is specified, the date is interpreted in your local timezone. The output always shows both UTC and local time for clarity.

タイムスタンプ変換ツールの使い方

Unixタイムスタンプ(秒またはミリ秒)を入力して「変換」を押すと、UTCとローカル時刻の両方で日時が表示されます。 逆に日時文字列からUnixタイムスタンプへの変換も可能です。「現在時刻」ボタンで今の時刻を全形式で確認でき、 全ての処理はブラウザ内で完結するため、データが外部に送信されることはありません。