public Date AddMonths(int months)
{
if (months < -120000 || months > 120000)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(months));
}
GetDatePart(out int y, out int m, out int d);
int i = m - 1 + months;
if (i >= 0)
{
m = i % 12 + 1;
y = y + i / 12;
}
else
{
m = 12 + (i + 1) % 12;
y = y + (i - 11) / 12;
}
if (y < 1 || y > 9999)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(months));
}
int days = DaysInMonth(y, m);
if (d > days)
{
d = days;
}
return(new Date((ulong)(DateToTicks(y, m, d) + InternalTicks % TicksPerDay) | InternalKind));
}
public Date AddYears(int value)
{
if (value < -10000 || value > 10000)
{
// DateTimeOffset.AddYears(int years) is implemented on top of DateTime.AddYears(int value). Use the more appropriate
// parameter name out of the two for the exception.
ExceptionThrower.ThrowArgumentOutOfRangeException("years");
}
return(AddMonths(value * 12));
}
internal Date(long ticks, DateTimeKind kind, bool isAmbiguousDst)
{
if (ticks < MinTicks || ticks > MaxTicks)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(ticks));
}
Debug.Assert(kind == DateTimeKind.Local, "Internal Constructor is for local times only");
_dateData = ((ulong)ticks | (isAmbiguousDst ? KindLocalAmbiguousDst : KindLocal));
}
public Date AddTicks(long value)
{
long ticks = InternalTicks;
if (value > MaxTicks - ticks || value < MinTicks - ticks)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(value));
}
return(new Date((ulong)(ticks + value) | InternalKind));
}
private Date Add(double value, int scale)
{
double millis_double = value * (double)scale + (value >= 0 ? 0.5 : -0.5);
if (millis_double <= (double)-MaxMillis || millis_double >= (double)MaxMillis)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(value));
}
return(AddTicks((long)millis_double * TicksPerMillisecond));
}
public Date Subtract(TimeSpan value)
{
long ticks = InternalTicks;
long valueTicks = value.Ticks;
if (ticks - MinTicks < valueTicks || ticks - MaxTicks > valueTicks)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(value));
}
return(new Date((ulong)(ticks - valueTicks) | InternalKind));
}
public static int DaysInMonth(int year, int month)
{
if (month < 1 || month > 12)
{
ExceptionThrower.ThrowArgumentOutOfRangeException(nameof(month));
}
// IsLeapYear checks the year argument
int[] days = IsLeapYear(year) ? s_daysToMonth366 : s_daysToMonth365;
return(days[month] - days[month - 1]);
}