仕組みと動作原理
DAYS関数はExcel業務を効率化する代表的な関数です。Returns the number of calendar days between two dates. 複雑な集計や参照処理を簡素化し、データ分析の精度と生産性を飛躍的に高めます。
構文.
標準Excel表記法=DAYS(end_date, start_date)引数一覧.
この関数で指定できるすべての引数について詳しく解説します。
The ending date in the interval.
指定例:B2The beginning date in the interval.
指定例:A2具体的な計算例
ステップ別の実務シナリオProject Timeline - Days Elapsed
Calculate the total calendar days between project kickoff and completion.
| Start Date | End Date | Days Elapsed |
|---|---|---|
| 2025-05-01 | 2025-05-31 | — |
| 2025-06-01 | 2025-06-15 | — |
=DAYS(B2, A2)Evaluates DAYS over the sample table cells, placing the verified output in cell C2.
数式ジェネレーター
ウィザードを開く引数を入力するだけで、シートにそのまま貼り付けて使える数式を作成できます。
=DAYS()出力される値の特性
Returns number 30 based on sample evaluation criteria and active cell references.
実務上のベストプラクティス
- Remember that end_date is listed first: =DAYS(end_date, start_date).
よくあるミスと注意点
- If start_date is later than end_date, DAYS returns a negative number.
各プラットフォーム対応表
実際のExcelおよびGoogleスプレッドシートの計算エンジン仕様に基づいた検証結果です。
Core standard function supported across all modern and legacy Microsoft Excel versions (365, 2021, 2019, 2016, 2013, 2010), as well as Excel for the Web and Mac.
100% compatible with Google Sheets. Uses identical argument order, data types, and standard calculation logic.
よくある質問と回答
技術解説Can I use DAYS across different worksheets in Excel?↓
Yes. You can reference cells located on other sheets by including the sheet name followed by an exclamation mark, for example: =DAYS(Sheet2!A2:A10). If the sheet name contains spaces, enclose it in single quotes: ='Q1 Report'!A2:A10.
What is the most common reason for errors in DAYS?↓
If start_date is later than end_date, DAYS returns a negative number.
Does DAYS work identically in Google Sheets?↓
Yes, DAYS is supported in both Microsoft Excel and Google Sheets with standard evaluation behavior.