Developer tools
日付形式・Unixタイムスタンプ・タイムゾーンを変換
日付形式の変換、Unixタイムスタンプ、DST対応のタイムゾーン変換、日付差の計算をブラウザだけで実行。アップロードなし。
日付形式を変え、Unixタイムスタンプと日付を相互変換し、世界のタイムゾーンを切り替えたり、2つの日付の差を計算できます。
- 端末内で実行
- アップロードなし
- すぐ変換
- 無料
All conversions run in your browser with native date APIs. Your inputs are not sent to a server.
Values like 01/02/2026 are ambiguous (Jan 2 vs Feb 1). Use the date picker or an ISO-style value such as 2026-02-01.
使い方
- 01 データを貼り付ける
- 02 実行する
- 03 結果をコピーする
NEXNARA を使う理由
-
非公開
データはブラウザ内に留まります。
-
すぐ変換
結果はすぐに表示されます。
-
アップロードなし
NEXNARA のサーバーには何も送りません。
-
どこでも使える
インストールは不要です。
詳しく見る
Convert date formats
Turn a clear date or date-time into common formats such as YYYY-MM-DD, MM/DD/YYYY, DD/MM/YYYY, ISO 8601, or a readable locale string—without uploading anything.
Convert Unix timestamps
Convert epoch seconds or milliseconds to UTC and local times, or turn a date into Unix timestamps. Auto-detect usually treats 10-digit values as seconds and 13-digit values as milliseconds.
Seconds vs milliseconds
Unix seconds count whole seconds since 1970-01-01 UTC. Milliseconds include three extra digits. When auto-detect is unsure, choose the unit explicitly.
Convert time zones
Pick a source IANA time zone, a target zone, and a wall-clock date/time. Results use real zone rules for that date—not a fixed offset.
UTC and local time
UTC is the reference clock. Your browser time zone is detected with Intl and can be applied with Use my zone.
Daylight saving time
Offsets change with daylight saving. For example, America/New_York is not always UTC−5. This tool applies the IANA rules for the date you enter.
Calculate the difference between dates
Compare two dates (with or without time) to see total days, hours, minutes, and seconds, plus a calendar breakdown of years, months, and days.
プライバシー
NEXNARA does not send your dates or timestamps to a server for this tool. Conversion happens in your browser.
What is a Unix timestamp?
A Unix timestamp counts seconds (or milliseconds) since 1970-01-01 00:00:00 UTC. It is a compact way to store an exact instant.
What is the difference between seconds and milliseconds?
Seconds are typically 10 digits around the present day. Milliseconds are usually 13 digits. The same instant is milliseconds = seconds × 1000.
How do I convert a timestamp to a date?
Open Unix Timestamp mode, paste the number, choose Auto-detect or the correct unit, then tap Timestamp → Date.
Can I convert UTC to local time?
Yes. In Time Zone mode set the source to UTC and the target to your zone, or use Unix mode which shows both UTC and local results.
Does the time zone converter handle daylight saving time?
Yes. It uses IANA time zone data via the browser, so DST rules for that date are applied instead of a hard-coded offset.
How do I find my local time zone?
Your browser zone is shown near the Time Zone controls. Use Use my zone to fill source or target.
Can I calculate days between two dates?
Yes. Date Difference mode reports total days and a calendar difference. Enable Compare dates only when times should be ignored.
Why can date formats like 01/02/2026 be ambiguous?
Some regions write month/day/year and others day/month/year. This tool does not guess—use the date picker or YYYY-MM-DD / ISO 8601.
Does NEXNARA send my date data to a server?
No. Date & Time Converter runs entirely in your browser for these conversions.