/// <summary>
/// Returns spot date for a given val date
/// e.g. for USD/ZAR, calendar would be for ZAR and otherCal would be for USD
/// </summary>
/// <param name="valDate"></param>
/// <param name="spotLag"></param>
/// <param name="calendar"></param>
/// <param name="otherCal"></param>
/// <returns></returns>
public static DateTime SpotDate(this DateTime valDate, Frequency spotLag, Calendar calendar, Calendar otherCal)
{
var d = valDate.AddPeriod(RollType.F, calendar, spotLag);
d = d.IfHolidayRollForward(otherCal);
return(d);
}
/// <summary>
/// Returns a date equal to the input date plus the specified period, adjusted for holidays
/// </summary>
/// <param name="date">Input date</param>
/// <param name="rollType">RollType enum</param>
/// <param name="calendar">Calendar</param>
/// <param name="datePeriod">Period to add in the form of a Frequency object</param>
/// <returns></returns>
public static DateTime AddPeriod(this DateTime date, RollType rollType, Calendar calendar, Frequency datePeriod)
{
if (calendar == null && datePeriod.PeriodType == DatePeriodType.B)
{
return(date);
}
date = date.Date;
if (datePeriod.PeriodCount == 0)
{
return(IfHolidayRoll(date, rollType, calendar));
}
if (datePeriod.PeriodType == DatePeriodType.B)
{
if (datePeriod.PeriodCount < 0) //actually a subtract
{
return(date.SubtractPeriod(rollType, calendar, new Frequency(-datePeriod.PeriodCount, datePeriod.PeriodType)));
}
//Business day jumping so we need to do something different
var d = date;
for (var i = 0; i < datePeriod.PeriodCount; i++)
{
d = d.AddDays(1);
d = IfHolidayRoll(d, rollType, calendar);
}
return(d);
}
DateTime dt;
switch (datePeriod.PeriodType)
{
case DatePeriodType.D:
dt = date.AddDays(datePeriod.PeriodCount);
break;
case DatePeriodType.M:
dt = date.AddMonths(datePeriod.PeriodCount);
break;
case DatePeriodType.W:
dt = date.AddDays(datePeriod.PeriodCount * 7);
break;
default:
dt = date.AddYears(datePeriod.PeriodCount);
break;
}
if ((rollType == RollType.MF_LIBOR) && (date == date.LastBusinessDayOfMonth(calendar)))
{
dt = date.LastBusinessDayOfMonth(calendar);
}
if (rollType == RollType.ShortFLongMF)
{
if (datePeriod.PeriodType == DatePeriodType.B || datePeriod.PeriodType == DatePeriodType.D || datePeriod.PeriodType == DatePeriodType.W)
{
return(IfHolidayRoll(dt, RollType.F, calendar));
}
else
{
return(IfHolidayRoll(dt, RollType.MF, calendar));
}
}
return(IfHolidayRoll(dt, rollType, calendar));
}
public static DateTime[] AddPeriod(this DateTime[] dates, RollType rollType, Calendar calendar, Frequency datePeriod) => dates.Select(d => d.AddPeriod(rollType, calendar, datePeriod)).ToArray();
/// <summary>
/// Returns the input date, adjusted by rolling if the input date falls on a holiday according to the specified calendar.
/// The type of roll is specfied in the input.
/// </summary>
/// <param name="date">Input date</param>
/// <param name="rollType">RollType enum</param>
/// <param name="calendar">Calendar</param>
/// <returns></returns>
public static DateTime IfHolidayRoll(this DateTime date, RollType rollType, Calendar calendar)
{
if (calendar == null)
{
return(date);
}
date = date.Date;
DateTime d, d1, d2;
double distFwd, distBack;
switch (rollType)
{
case RollType.F:
return(date.IfHolidayRollForward(calendar));
case RollType.MF:
default:
d = date.IfHolidayRollForward(calendar);
if (d.Month == date.Month)
{
return(d);
}
else
{
return(date.IfHolidayRollBack(calendar));
}
case RollType.P:
return(date.IfHolidayRollBack(calendar));
case RollType.MP:
d = date.IfHolidayRollBack(calendar);
if (d.Month == date.Month)
{
return(d);
}
else
{
return(date.IfHolidayRollForward(calendar));
}
case RollType.NearestFollow:
d1 = date.IfHolidayRollForward(calendar);
d2 = date.IfHolidayRollBack(calendar);
distFwd = (d1 - date).TotalDays;
distBack = (date - d2).TotalDays;
if (distBack < distFwd)
{
return(d2);
}
else
{
return(d1);
}
case RollType.NearestPrev:
d1 = date.IfHolidayRollForward(calendar);
d2 = date.IfHolidayRollBack(calendar);
distFwd = (d1 - date).TotalDays;
distBack = (date - d2).TotalDays;
if (distFwd < distBack)
{
return(d1);
}
else
{
return(d2);
}
case RollType.LME:
d1 = date.IfHolidayRollForward(calendar);
if (d1.Month != date.Month)
{
return(date.IfHolidayRollBack(calendar));
}
d2 = date.IfHolidayRollBack(calendar);
if (d2.Month != date.Month)
{
return(d1);
}
distFwd = (d1 - date).TotalDays;
distBack = (date - d2).TotalDays;
if (distBack < distFwd)
{
return(d2);
}
else
{
return(d1);
}
case RollType.None:
return(date);
}
}
/// <summary>
/// Returns last business day, according to the specified calendar, of the month in which the input date falls
/// </summary>
/// <param name="input">Input date</param>
/// <param name="calendar">Calendar</param>
/// <returns></returns>
public static DateTime LastBusinessDayOfMonth(this DateTime input, Calendar calendar)
{
var d = input.Date.AddMonths(1).FirstDayOfMonth();
return(SubtractPeriod(d, RollType.P, calendar, 1.Bd()));
}
/// <summary>
/// Calculates a year fraction from a day count method and two dates
/// Start date is inclusive, end date exclusive
/// </summary>
/// <param name="startDate">Start Date (inclusive)</param>
/// <param name="endDate">End Date (exclusive)</param>
/// <param name="basis">DayCountBasis enum</param>
/// <param name="ignoreTimeComponent">Ignore the time component of the DateTime inputs - defaults to true</param>
/// <param name="calendar">Optional calendar object, required only for methods involving business days</param>
/// <returns></returns>
public static double CalculateYearFraction(this DateTime startDate, DateTime endDate, DayCountBasis basis, bool ignoreTimeComponent = true, Calendar calendar = null)
{
if (ignoreTimeComponent)
{
startDate = startDate.Date;
endDate = endDate.Date;
}
switch (basis)
{
case DayCountBasis.Act_360:
return((endDate.Ticks - startDate.Ticks) * _ticksFraction360);
case DayCountBasis.Act_365F:
return((endDate.Ticks - startDate.Ticks) * _ticksFraction365);
case DayCountBasis.Act_Act_ISDA:
case DayCountBasis.Act_Act:
if (endDate.Year == startDate.Year)
{ //simple case
var eoY = new DateTime(endDate.Year, 12, 31);
return((endDate - startDate).TotalDays / eoY.DayOfYear);
}
else
{
double nIntermediateYears = endDate.Year - startDate.Year - 1;
var eoYe = new DateTime(endDate.Year, 12, 31);
var e = endDate.DayOfYear / (double)eoYe.DayOfYear;
var eoYs = new DateTime(startDate.Year, 12, 31);
var s = (eoYs - startDate).TotalDays / eoYs.DayOfYear;
return(s + nIntermediateYears + e);
}
case DayCountBasis._30_360:
double ydiff = endDate.Year - startDate.Year;
double mdiff = endDate.Month - startDate.Month;
double ddiff = endDate.Day - startDate.Day;
return((ydiff * 360 + mdiff * 30 + ddiff) / 360);
case DayCountBasis.ThirtyE360:
double d1E = Math.Min(startDate.Day, 30);
double d2E = Math.Min(endDate.Day, 30);
double ydiffE = endDate.Year - startDate.Year;
double mdiffE = endDate.Month - startDate.Month;
var ddiffE = d2E - d1E;
return((ydiffE * 360 + mdiffE * 30 + ddiffE) / 360);
case DayCountBasis.Bus252:
return(startDate.BusinessDaysInPeriod(endDate.AddDays(-1), calendar).Count / 252.0);
case DayCountBasis.Unity:
return(1.0);
}
return(-1);
}
/// <summary>
/// Returns a list of friday dates according to a specified calendar which are contained within two given dates.
/// If a friday is a holiday, the preceeding good business day is returned
/// Start and end dates are treated as inclusive
/// </summary>
/// <param name="startDateInc"></param>
/// <param name="endDateInc"></param>
/// <param name="calendars"></param>
/// <returns></returns>
public static List <DateTime> FridaysInPeriod(this DateTime startDateInc, DateTime endDateInc, Calendar calendars)
{
if (endDateInc < startDateInc)
{
throw new ArgumentException(nameof(endDateInc), "End date is before the start date");
}
var o = new List <DateTime>((int)(endDateInc - startDateInc).TotalDays);
var date = startDateInc;
while (date <= endDateInc)
{
if (date.DayOfWeek == DayOfWeek.Friday)
{
o.Add(date.IfHolidayRoll(RollType.P, calendars));
}
date = date.AddPeriod(RollType.None, null, 1.Day());
}
return(o);
}
/// <summary>
/// Returns a list of business dates according to a specified calendar which are contained within two given dates.
/// Start and end dates are treated as inclusive
/// </summary>
/// <param name="startDateInc"></param>
/// <param name="endDateInc"></param>
/// <param name="calendars"></param>
/// <returns></returns>
public static List <DateTime> BusinessDaysInPeriod(this DateTime startDateInc, DateTime endDateInc, Calendar calendars)
{
if (endDateInc < startDateInc)
{
throw new ArgumentException(nameof(endDateInc), "End date is before the start date");
}
var o = new List <DateTime>((int)(endDateInc - startDateInc).TotalDays);
var date = startDateInc.IfHolidayRollForward(calendars);
while (date <= endDateInc)
{
o.Add(date);
date = date.AddPeriod(RollType.F, calendars, 1.Bd());
}
return(o);
}
