曜日計算機

共有リンク

はじめに

Day of the Week Calculator — Find what day of the week any date falls on. Enter Date to get an instant, accurate result.

計算式

Looks up the day name for any given date using standard calendar-day arithmetic, and flags Saturday and Sunday as weekend days.

ステップごとの説明

Enter the Date.
Click Calculate to see your result instantly.

実例

Example: With Date = 2026-10-09, the Day of the Week Calculator gives Day Name: Friday, Day Short: Fri, Is Weekend: no.

よくある質問

Can I check a date far in the past or future?

Yes, any valid calendar date works, whether centuries ago or far in the future.

Which days count as weekend?

Saturday and Sunday; Monday through Friday are treated as weekdays.

What inputs does the Day of the Week Calculator need?

You'll need to provide: Date. All fields use sensible defaults, so you can see a working example immediately and then adjust the values to match your own numbers.

How accurate is the Day of the Week Calculator?

The Day of the Week Calculator applies the formula exactly as calculated — Looks up the day name for any given date using standard calendar-day arithmetic, and flags Saturday and Sunday as weekend days. — so results are precise for the inputs you provide. Accuracy depends on entering correct, realistic input values.

Is the Day of the Week Calculator free to use?

Yes, the Day of the Week Calculator is completely free, requires no signup, and runs instantly in your browser.