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100日・記念日計算
開始日を入力すると、100日目・200日目・300日目・満1年・500日目・1000日目の日付が分かります。
お気に入りにするとホームですぐに探せます
How to use it
1Step 1Fill in Start date
2Step 2Change a value and the result updates instantly
3Step 3Save or copy the result with Calculate
If the result looks off
The result looks wrong
Check the units and the baseline first. Changing a value updates the result instantly.
I want the starting values back
Press reset to return to the initial state.
よくある質問
Is the start day counted?
Yes — the start date counts as day one, the usual way anniversaries are counted.
Can I use it for a work anniversary?
Yes, any start date works — a job, a move, a first meeting.