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A date difference calculator computes the exact number of days, weeks, months, and years between two calendar dates. Useful for countdown timers, age calculations, contract duration, and deadline tracking. Accounting for leap years makes this non-trivial: 2000 had 366 days, most centuries do not.

ステップバイステップガイド

1. 1Enter start and end dates
2. 2Calculate difference in days
3. 3Convert to years/months/days

解いた例

避けるべきよくある間違い

• ✕Not double-checking results
• ✕Ignoring edge cases

よくある質問