Easily calculate the next time at which a recurring event occurs. Uses a fluent syntax.
PM> Install-Package Dates.Recurring
// Daily recurrences
var daily = Recurs
.Starting(new DateTime(2015, 1, 1))
.Every(1)
.Days()
.Ending(new DateTime(2015, 1, 15))
.Build();
daily.Next(new DateTime(2014, 7, 3)); // 2015/01/01
daily.Next(new DateTime(2015, 1, 1)); // 2015/01/02
daily.Next(new DateTime(2015, 1, 2)); // 2015/01/03
daily.Next(new DateTime(2015, 1, 15)); // null
// Weekly recurrences
var weekly = Recurs
.Starting(new DateTime(2015, 1, 1))
.Every(1)
.Weeks()
.FirstDayOfWeek(DayOfWeek.Monday)
.OnDays(Day.TUESDAY | Day.FRIDAY)
.Ending(new DateTime(2015, 2, 19))
.Build();
weekly.Next(new DateTime(2014, 1, 1)); // 2015/01/02
weekly.Next(new DateTime(2015, 1, 2)); // 2015/01/06
weekly.Next(new DateTime(2014, 1, 6)); // 2015/01/09
weekly.Next(new DateTime(2014, 1, 9)); // 2015/01/13
// Monthly recurrences on a set day of the month
var monthly = Recurs
.Starting(new DateTime(2015, 1, 1))
.Every(1)
.Months()
.OnDay(24)
.Ending(new DateTime(2016, 2, 4))
.Build();
monthly.Next(new DateTime(2014, 4, 8)); // 2015/01/24
monthly.Next(new DateTime(2015, 1, 24)); // 2015/02/24
monthly.Next(new DateTime(2015, 2, 24)); // 2015/03/24
monthly.Next(new DateTime(2015, 2, 10)); // 2015/03/24
// Monthly recurrences on an ordinal week and day of the week
var monthly = Recurs
.Starting(new DateTime(2018, 1, 1)) // Monday
.Every(1)
.Months()
.OnOrdinalWeek(Ordinal.SECOND)
.OnDay(DayOfWeek.Friday)
.Ending(new DateTime(2018, 12, 25))
.Build();
monthly.Next(new DateTime(2017, 1, 1)); // 2018/01/12
monthly.Next(new DateTime(2018, 1, 1)); // 2018/01/12
monthly.Next(new DateTime(2018, 2, 1)); // 2018/02/09
monthly.Next(new DateTime(2018, 9, 1)); // 2018/09/14
monthly.Next(new DateTime(2020, 2, 1)); // null
// Yearly recurrences on particular days of the month
var yearly = Recurs
.Starting(new DateTime(2015, 1, 1))
.Every(1)
.Years()
.OnDay(24)
.OnMonths(Month.JANUARY | Month.FEBRUARY | Month.AUGUST)
.Ending(new DateTime(2020, 1, 1))
.Build();
yearly.Next(new DateTime(2014, 1, 1)); // 2015/01/24
yearly.Next(new DateTime(2015, 1, 1)); // 2015/01/24
yearly.Next(new DateTime(2015, 1, 23)); // 2015/01/24
yearly.Next(new DateTime(2014, 1, 24)); // 2015/02/24
yearly.Next(new DateTime(2014, 2, 24)); // 2015/08/24
// Yearly recurrences on ordinal week, day of week and in January
var yearly = Recurs
.Starting(new DateTime(2018, 1, 1))
.Every(1)
.Years()
.OnOrdinalWeek(Ordinal.THIRD)
.OnDay(DayOfWeek.Thursday)
.OnMonths(Month.JANUARY)
.Ending(new DateTime(2030, 1, 1))
.Build();
yearly.Next(new DateTime(2014, 1, 1)); // 2018/01/18
yearly.Next(new DateTime(2018, 1, 1)); // 2018/01/18
yearly.Next(new DateTime(2018, 1, 18)); // 2019/01/17
yearly.Next(new DateTime(2019, 2, 18)); // 2020/01/16
yearly.Next(new DateTime(2030, 1, 1)); // null