タイムスタンプ変換器
トレンド 🔥Unixタイムスタンプを日付に変換
タイムスタンプ変換器 の使い方
- 1Unix タイムスタンプまたは読みやすい日付を入力
- 2時間精度を選択
- 3すべての時間表現を確認
タイムスタンプ変換器 について
タイムスタンプコンバーターは Unix/Epoch タイムスタンプと人間が読みやすい日時の間で変換するツールです。
タイムスタンプ変換器の主な機能
- Convert Unix timestamps to human-readable date and time
- Convert dates to Unix timestamps (seconds and milliseconds)
- Auto-detects seconds vs milliseconds based on timestamp length
- Displays results in UTC, local time, and ISO 8601 format
- Shows the current Unix timestamp updated every second
- Works entirely in-browser using the JavaScript Date API
- One-click copy for each output format
- Relative time display (e.g., "3 days ago" or "in 2 hours")
使用例
Convert a timestamp from an API log to a readable date
Find out what date and time a Unix timestamp in a server log represents.
入力
1700000000
出力
UTC: Wed Nov 14 2023 22:13:20 UTC | ISO 8601: 2023-11-14T22:13:20.000Z
Get the Unix timestamp for a specific date
Find the timestamp to use as a parameter in an API query.
入力
2024-01-01 00:00:00 UTC
出力
Seconds: 1704067200 | Milliseconds: 1704067200000
主な使用ケース
- Decoding timestamps from server logs, database records, and API responses
- Checking token expiration times (exp claims in JWTs) stored as Unix timestamps
- Generating timestamp values for API query parameters (date range filters)
- Debugging time-related issues by converting timestamps to readable dates
- Verifying that a scheduled job or cron expression ran at the expected time
- Converting timestamps for use in SQL queries with date comparison operators
トラブルシューティング
Timestamp converts to a date in 1970 or a very early date
解決策
This usually means the timestamp is in seconds but was treated as milliseconds (or vice versa). A 10-digit number is typically seconds; a 13-digit number is milliseconds. The tool auto-detects this based on length.
Date shows the correct day but wrong time
解決策
Unix timestamps are always in UTC. The local time display depends on your browser's timezone setting. Check both the UTC and local time outputs to confirm which is relevant for your use case.
Negative timestamp value
解決策
Negative Unix timestamps represent dates before January 1, 1970. For example, -86400 represents December 31, 1969. These are valid and handled correctly by the tool.
よくある質問
What is a Unix timestamp?
A Unix timestamp is the number of seconds (or milliseconds) elapsed since the Unix epoch: January 1, 1970, 00:00:00 UTC. It is a timezone-agnostic representation of a moment in time used universally in programming and databases.
How do I know if a timestamp is in seconds or milliseconds?
A 10-digit number is typically in seconds (valid until year 2286). A 13-digit number is typically in milliseconds. The tool auto-detects this based on the length of the input.
What is the Unix epoch?
The Unix epoch is the reference point for Unix timestamps: January 1, 1970, 00:00:00 UTC. All timestamps are the number of seconds (or milliseconds) counted from this moment.
What is ISO 8601 format?
ISO 8601 is an international standard for representing dates and times as strings, for example: 2023-11-14T22:13:20.000Z. The Z suffix indicates UTC. It is widely used in APIs, JSON, and log files.
Can Unix timestamps represent dates before 1970?
Yes. Negative timestamps represent dates before January 1, 1970. For example, -86400 is December 31, 1969. Both positive and negative timestamps are fully supported.
What is the maximum Unix timestamp value?
The maximum 32-bit signed Unix timestamp is 2,147,483,647, which corresponds to January 19, 2038. This is the "Year 2038 problem" for 32-bit systems. JavaScript uses 64-bit integers, supporting timestamps far beyond this date.
Is my data sent to a server?
No. All timestamp conversion is performed locally in your browser using the JavaScript Date object. No data is transmitted or stored.
Can I get the timestamp for a specific timezone?
Unix timestamps are always UTC. To work with timezone-specific times, use the Timezone Converter to adjust the display. Timestamps themselves are timezone-agnostic — only the human-readable representation changes by timezone.