10 vs 13 digits
10 digits usually indicate seconds; 13 digits usually indicate milliseconds.
ミリ秒タイムスタンプ変換
13桁のミリ秒 timestamp を変換し、10桁の Unix 秒と比較して単位ミスを防ぎます。
解決できること
JavaScript Date.now()、フロントエンドログ、分析イベント、ミリ秒保存の値に使います。
使い方
- Copy the 13-digit timestamp from JavaScript, logs, or analytics data.
- Paste it into the main timestamp tool.
- Compare the millisecond and second outputs.
- Copy the correct unit for the target API or report.
Milliseconds example
1700000000000 1700000000
1700000000000 milliseconds equals 1700000000 seconds when divided by 1000.
If a date appears far in the future, a millisecond value may have been treated as seconds.
よくあるミス
Dividing twice
Do not divide by 1000 again if the tool already gives seconds output.
Unexpected future dates
Large values can produce unrealistic dates if interpreted with the wrong unit.
ミリ秒 timestamp FAQ
What does Date.now() return?
JavaScript Date.now() returns milliseconds since the Unix epoch.
How do I convert milliseconds to seconds?
Divide the millisecond timestamp by 1000, or copy the seconds output from the tool.
Why are there 13 digits?
Milliseconds need three extra digits compared with Unix seconds.