Excel で日付の条件付き書式(期限超過、近日、週末)

日付列に数式ルールを適用し、範囲の先頭セル向けに書きます。期限 F1 に対する超過は =A2<$F$1 です。週末は WEEKDAY の種類 2(月曜が 1、日曜が 7)で土曜が 6、日曜が 7 なので =OR(WEEKDAY(A2,2)=6,WEEKDAY(A2,2)=7) です。セルは実際の日付で、日付に見える文字列ではいけません。

目次

要点

日付列に数式ルールを適用し、範囲の先頭セル向けに書きます。期限 F1 に対する超過は =A2<$F$1 です。週末は WEEKDAY の種類 2(月曜が 1、日曜が 7)で土曜が 6、日曜が 7 なので =OR(WEEKDAY(A2,2)=6,WEEKDAY(A2,2)=7) です。セルは実際の日付で、日付に見える文字列ではいけません。

=A2<DATE(2024,3,1)

確認のポイント

2026年11月12日の確認では DATE(2024,2,20)<DATE(2024,3,1) は TRUE、3月1日と3月4日は FALSE でした。WEEKDAY(DATE(2024,3,4),2) は 1(月曜)、WEEKDAY(DATE(2024,3,9),2) は 6(土曜)です。今後7日は =AND(A2>=$F$1,A2<=$F$1+7) です。

注意点と互換性

ISNUMBER(A2) が FALSE なら文字列の日付で、比較が期待どおりに塗られないことがあるので先に変換します。範囲が A2 からなのに =A1<$F$1 と書くと1行ずれます。TODAY() は毎日変わるので、テスト用には DATE かセルの方が安全です。先に補助列で同じ数式の TRUE または FALSE を確認してから色を頼ります。

英語の詳細例・数式・著者メモ

Tested in: The date comparisons and WEEKDAY results below were evaluated in Google Sheets on 12 November 2026. Excel 365 menu names are the current desktop labels; I did not click through Conditional Formatting in Excel this session.

The general feature guide is in Conditional Formatting in Excel. If a formula rule highlights the wrong rows, see formula not working. This page is only about date rules.

Overdue against a cutoff

Pick a cutoff you can test. In the test workbook the cutoff was 1 March 2024:

=A2<DATE(2024,3,1)

or, with the cutoff in F1:

=A2<$F$1

On 12 November 2026, =DATE(2024,2,20)<DATE(2024,3,1) was TRUE, and the same comparison for 1 March and for 4 March was FALSE. A due date that equals the cutoff is not overdue under a strict < rule; use <= if the due date itself should count.

Apply the rule to A2:A100 (or however long the list is), not to A1 if A1 is a header. To color the entire row, apply it to A2:F100 and lock the date column: =$A2<$F$1.

TODAY() is fine when you want the cutoff to move: =A2<TODAY(). I did not evaluate TODAY() in the test workbook on a frozen date, because it would change tomorrow. For a screenshot or a test file, prefer DATE or a cell.

Upcoming dates, and weekends

A window from the cutoff through the next seven days:

=AND(A2>=$F$1,A2<=$F$1+7)

If F1 is 1 March 2024, 4 March is inside that window and 20 February is not.

For weekends, use WEEKDAY with return type 2 so Monday is 1 and Sunday is 7:

=OR(WEEKDAY(A2,2)=6,WEEKDAY(A2,2)=7)

In the test workbook, =WEEKDAY(DATE(2024,3,4),2) returned 1 (4 March 2024 was a Monday) and =WEEKDAY(DATE(2024,3,9),2) returned 6 (a Saturday). Type 1 of WEEKDAY is different (Sunday = 1); do not mix the two types in the same rule.

Google Sheets uses the same formulas in Format > Conditional formatting > Custom formula is.

When the rule does nothing

If =ISNUMBER(A2) is FALSE, the cell is text that looks like a date, and a comparison against DATE or TODAY() will not highlight it reliably. Convert the column first, as in dates stored as text.

A rule written as =A1<$F$1 on a range that starts at A2 is aimed one row too high. A cutoff typed as 2024-03-01 but stored as text is the same class of problem as text dates in the list.

Built-in rules such as A Date Occurring > Yesterday can work for quick filters, but a formula you can test in a helper column is easier to check. Put =A2<$F$1 next to the first date, fill down, and confirm the TRUE/FALSE pattern before you rely on the color.

Oscar

表計算の数式とトラブル解決を紹介。検証環境と未確認事項は各記事を参照。

Tested in Google Sheets (via Sheets API) on 12 November 2026: DATE(2024,2,20)<DATE(2024,3,1) is TRUE; the same comparison on 2024-03-01 and on 2024-03-04 is FALSE; WEEKDAY of 2024-03-04 with type 2 is 1 (Monday) and of 2024-03-09 is 6 (Saturday). Excel 365 menu names are the current desktop labels; I did not click through the Conditional Formatting dialog in Excel this session..

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