C# TimeSpan

TimeSpan型の値は、DateTime型の値の差を表します。 

TimeSpan.Daysで差の日数がわかります。

 1ミリ秒や1ティックでも短いと日数に換算されないようです。

DateTime.Dateの差使うと日付を比較できます。
 

        DateTime today = DateTime.Now;
        DateTime yesterday = today.AddDays(-1).AddMinutes(1);
        DateTime tomorrow = today.AddDays(1);

        Debug.Log("yesterday: " + yesterday);
        Debug.Log("today: " + today);
        Debug.Log("tomorrow: " + tomorrow);

        TimeSpan timeSpan = today - yesterday;

        Debug.Log("today - yesterday: " + timeSpan.Days);

         timeSpan = tomorrow - today;

        Debug.Log("tomorrow - today: " + timeSpan.Days);

         timeSpan = today.Date - yesterday.Date;

        Debug.Log("today.Date - yesterday.Date: " + timeSpan.Days);

        timeSpan = tomorrow.Date - today.Date;

        Debug.Log("tomorrow.Date - today.Date: " + timeSpan.Days);