public static DateTime Truncate(this DateTime dateTime, DateTimeSignificance significance)
{
int year = dateTime.Year;
int month = 1, day = 1, hour = 0, minute = 0, second = 0;
if (significance != DateTimeSignificance.ToYears)
{
month = dateTime.Month;
if (significance != DateTimeSignificance.ToMonths)
{
day = dateTime.Day;
if (significance != DateTimeSignificance.ToDays)
{
hour = dateTime.Hour;
if (significance != DateTimeSignificance.ToHours)
{
minute = dateTime.Minute;
if (significance != DateTimeSignificance.ToMinutes)
{
second = dateTime.Second;
}
}
}
}
}
return(new DateTime(year, month, day, hour, minute, second, dateTime.Kind));
}
// ==========================================================================
//
// Truncation
//
// ==========================================================================
public static DateTime Round(this DateTime dateTime, DateTimeSignificance significance)
{
DateTime result;
int year = dateTime.Year;
int month = dateTime.Month;
if (significance != DateTimeSignificance.ToYears)
{
int day = dateTime.Day;
if (significance != DateTimeSignificance.ToMonths)
{
int hour = dateTime.Hour;
if (significance != DateTimeSignificance.ToDays)
{
int minute = dateTime.Minute;
if (significance != DateTimeSignificance.ToHours)
{
int second = dateTime.Second;
if (significance != DateTimeSignificance.ToMinutes)
{
// Seconds
result = new DateTime(year, month, day, hour, minute, second, dateTime.Kind);
if (dateTime.Millisecond >= 500)
{
result = result.AddSeconds(1);
}
}
else // minutes
{
result = new DateTime(year, month, day, hour, minute, 0, dateTime.Kind);
if (second >= 30)
{
result = result.AddMinutes(1);
}
}
}
else // hours
{
result = new DateTime(year, month, day, hour, 0, 0, dateTime.Kind);
if (minute >= 30)
{
result = result.AddHours(1);
}
}
}
else // day
{
result = new DateTime(year, month, day, 0, 0, 0, dateTime.Kind);
if (hour >= 12)
{
result = result.AddDays(1);
}
}
}
else // month
{
result = new DateTime(year, month, 1);
int dayThreshold = 16;
int daysInMonth = DateTime.DaysInMonth(year, month);
if (daysInMonth == 30 || daysInMonth == 29)
{
dayThreshold = 15;
}
else if (daysInMonth == 28)
{
dayThreshold = 14;
}
if (day > dayThreshold)
{
result = result.AddMonths(1);
}
}
}
else
{
if (month >= 7)
{
year++;
}
result = new DateTime(year, 1, 1, 0, 0, 0, dateTime.Kind);
}
return(result);
}
public static int CompareTo(this DateTime dateTime, DateTime dateToCompare, DateTimeSignificance significance)
{
int yearsDelta = dateTime.Year - dateToCompare.Year;
if (yearsDelta != 0)
{
return(yearsDelta < 0 ? -1 : 1);
}
if (significance == DateTimeSignificance.ToYears)
{
return(0);
}
int monthsDelta = dateTime.Month - dateToCompare.Month;
if (monthsDelta != 0)
{
return(monthsDelta < 0 ? -1 : 1);
}
if (significance == DateTimeSignificance.ToMonths)
{
return(0);
}
int daysDelta = dateTime.Day - dateToCompare.Day;
if (daysDelta != 0)
{
return(daysDelta < 0 ? -1 : 1);
}
if (significance == DateTimeSignificance.ToDays)
{
return(0);
}
int hoursDelta = dateTime.Hour - dateToCompare.Hour;
if (hoursDelta != 0)
{
return(hoursDelta < 0 ? -1 : 1);
}
if (significance == DateTimeSignificance.ToHours)
{
return(0);
}
int minutesDelta = dateTime.Minute - dateToCompare.Minute;
if (minutesDelta != 0)
{
return(minutesDelta < 0 ? -1 : 1);
}
if (significance == DateTimeSignificance.ToMinutes)
{
return(0);
}
int secondsDelta = dateTime.Second - dateToCompare.Second;
if (secondsDelta != 0)
{
return(secondsDelta < 0 ? -1 : 1);
}
return(0);
}
public static DateTime Truncate(this DateTime dateTime, DateTimeSignificance significance)
{
int year = dateTime.Year;
int month = 1, day = 1, hour = 0, minute = 0, second = 0;
if (significance != DateTimeSignificance.ToYears)
{
month = dateTime.Month;
if (significance != DateTimeSignificance.ToMonths)
{
day = dateTime.Day;
if (significance != DateTimeSignificance.ToDays)
{
hour = dateTime.Hour;
if (significance != DateTimeSignificance.ToHours)
{
minute = dateTime.Minute;
if (significance != DateTimeSignificance.ToMinutes)
{
second = dateTime.Second;
}
}
}
}
}
return new DateTime(year, month, day, hour, minute, second, dateTime.Kind);
}
// ==========================================================================
//
// Truncation
//
// ==========================================================================
public static DateTime Round(this DateTime dateTime, DateTimeSignificance significance)
{
DateTime result;
int year = dateTime.Year;
int month = dateTime.Month;
if (significance != DateTimeSignificance.ToYears)
{
int day = dateTime.Day;
if (significance != DateTimeSignificance.ToMonths)
{
int hour = dateTime.Hour;
if (significance != DateTimeSignificance.ToDays)
{
int minute = dateTime.Minute;
if (significance != DateTimeSignificance.ToHours)
{
int second = dateTime.Second;
if (significance != DateTimeSignificance.ToMinutes)
{
// Seconds
result = new DateTime(year, month, day, hour, minute, second, dateTime.Kind);
if (dateTime.Millisecond >= 500)
result = result.AddSeconds(1);
}
else // minutes
{
result = new DateTime(year, month, day, hour, minute, 0, dateTime.Kind);
if (second >= 30)
result = result.AddMinutes(1);
}
}
else // hours
{
result = new DateTime(year, month, day, hour, 0, 0, dateTime.Kind);
if (minute >= 30)
result = result.AddHours(1);
}
}
else // day
{
result = new DateTime(year, month, day, 0, 0, 0, dateTime.Kind);
if (hour >= 12)
result = result.AddDays(1);
}
}
else // month
{
result = new DateTime(year, month, 1);
int dayThreshold = 16;
int daysInMonth = DateTime.DaysInMonth(year, month);
if (daysInMonth == 30 || daysInMonth == 29)
{
dayThreshold = 15;
}
else if (daysInMonth == 28)
{
dayThreshold = 14;
}
if (day > dayThreshold)
{
result = result.AddMonths(1);
}
}
}
else
{
if (month >= 7)
year++;
result = new DateTime(year, 1, 1, 0, 0, 0, dateTime.Kind);
}
return result;
}
public static int CompareTo(this DateTime dateTime, DateTime dateToCompare, DateTimeSignificance significance)
{
int yearsDelta = dateTime.Year - dateToCompare.Year;
if (yearsDelta != 0)
return yearsDelta < 0 ? -1 : 1;
if (significance == DateTimeSignificance.ToYears)
return 0;
int monthsDelta = dateTime.Month - dateToCompare.Month;
if (monthsDelta != 0)
return monthsDelta < 0 ? -1 : 1;
if (significance == DateTimeSignificance.ToMonths)
return 0;
int daysDelta = dateTime.Day - dateToCompare.Day;
if (daysDelta != 0)
return daysDelta < 0 ? -1 : 1;
if (significance == DateTimeSignificance.ToDays)
return 0;
int hoursDelta = dateTime.Hour - dateToCompare.Hour;
if (hoursDelta != 0)
return hoursDelta < 0 ? -1 : 1;
if (significance == DateTimeSignificance.ToHours)
return 0;
int minutesDelta = dateTime.Minute - dateToCompare.Minute;
if (minutesDelta != 0)
return minutesDelta < 0 ? -1 : 1;
if (significance == DateTimeSignificance.ToMinutes)
return 0;
int secondsDelta = dateTime.Second - dateToCompare.Second;
if (secondsDelta != 0)
return secondsDelta < 0 ? -1 : 1;
return 0;
}