Usually I create Fowler's Range implementation for such things.
public interface IRange<T>
{
T Start { get; }
T End { get; }
bool Includes(T value);
bool Includes(IRange<T> range);
}
public class DateRange : IRange<DateTime>
{
public DateRange(DateTime start, DateTime end)
{
Start = start;
End = end;
}
public DateTime Start { get; private set; }
public DateTime End { get; private set; }
public bool Includes(DateTime value)
{
return (Start <= value) && (value <= End);
}
public bool Includes(IRange<DateTime> range)
{
return (Start <= range.Start) && (range.End <= End);
}
}
Usage is pretty simple:
DateRange range = new DateRange(startDate, endDate);
range.Includes(date)