仕組みと動作原理
TODAY関数はExcel業務を効率化する代表的な関数です。現在の日付をシリアル値として返します。ブックを開くたびに自動更新されます。 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。
💡 わかりやすい要約
Returns the current date. It updates itself automatically every single day.
"Think of this like a digital calendar on your wall. Every single morning, it automatically flips to show today's date."
構文.
標準Excel表記法=TODAY()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。
引数は不要です。カッコだけを付けて実行します。
具体的な計算例
ステップ別の実務シナリオCalculate Days Overdue
Calculate how many days are left (or overdue) relative to today's date.
| Due Date | Days Elapsed | System Date Symbol | ||
|---|---|---|---|---|
| 2026-08-01 | — | TODAY() | — | — |
| 2026-08-10 | — | — | — | — |
| 2026-08-15 | — | — | — | — |
=TODAY() - A2Evaluates TODAY over the sample table cells, placing the verified output in cell B2:B6.
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。
=TODAY()
=TODAY()出力される値の特性
Returns "2026-10-10" based on sample evaluation criteria and active cell references.
実務上のベストプラクティス
- TODAY is excellent for calculating age, duration, or days remaining (e.g. `=A2 - TODAY()` calculates days until a deadline date in A2).
- If you need both the date and current system time, use `=NOW()` instead.
よくあるミスと注意点
- TODAY is a volatile function. It can slow down large spreadsheets because it forces a recalculation of the entire sheet every time *any* cell changes.
- Do not use TODAY if you want a permanent timestamp that stays fixed.
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 TODAY 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: =TODAY(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 TODAY?↓
TODAY is a volatile function. It can slow down large spreadsheets because it forces a recalculation of the entire sheet every time *any* cell changes.
Does TODAY work identically in Google Sheets?↓
Yes, TODAY is supported in both Microsoft Excel and Google Sheets with standard evaluation behavior.