public static DateTime GetDateFromDynamic(DateMagnitude magnitude, int offset, bool isEndDate, DateTimeOffset todaysDate, DayOfWeek weekStart, TimeZoneInfo timeZone)
{
var localToday = TimeZoneInfo.ConvertTime(todaysDate, timeZone);
DateTimeOffset result;
if (isEndDate) offset++;
switch (magnitude)
{
case DateMagnitude.BusinessDay:
var offsetMagn = Math.Abs(offset);
var offsetSign = Math.Sign(offset);
var i = 0;
result = localToday;
while (i < offsetMagn)
{
result = result.AddDays(offsetSign);
if (result.DayOfWeek != DayOfWeek.Sunday && result.DayOfWeek != DayOfWeek.Saturday)
i++;
}
break;
case DateMagnitude.Week:
result = GetWeekStart(todaysDate, weekStart).AddDays(offset * 7);
break;
case DateMagnitude.Month:
result = new DateTimeOffset(todaysDate.Year, todaysDate.Month, 1, 0, 0, 0, localToday.Offset).AddMonths(offset);
break;
case DateMagnitude.Quarter:
switch (todaysDate.Month)
{
case 1:
case 2:
case 3:
result = new DateTimeOffset(todaysDate.Year, 1, 1, 0, 0, 0, localToday.Offset).AddMonths(offset * 3);
break;
case 4:
case 5:
case 6:
result = new DateTimeOffset(todaysDate.Year, 4, 1, 0, 0, 0, localToday.Offset).AddMonths(offset * 3);
break;
case 7:
case 8:
case 9:
result = new DateTimeOffset(todaysDate.Year, 7, 1, 0, 0, 0, localToday.Offset).AddMonths(offset * 3);
break;
default:
result = new DateTimeOffset(todaysDate.Year, 10, 1, 0, 0, 0, localToday.Offset).AddMonths(offset * 3);
break;
}
break;
case DateMagnitude.Year:
result = new DateTimeOffset(todaysDate.Year, 1, 1, 0, 0, 0, localToday.Offset).AddYears(offset * 3);
break;
default:
result = todaysDate.AddDays(offset);
break;
}
if (isEndDate) return result.Date.AddMilliseconds(-1);
return result.Date;
}
/// <summary>
/// Initializes a structure to represent a relative date specified by a magnitude and offset
/// </summary>
/// <param name="offset">The amount of time units to offset.</param>
/// <param name="magnitude">The magnitude of the offset (e.g. days, weeks, months, etc).</param>
public DateOffset(short offset, DateMagnitude magnitude)
{
_offset = offset;
Magnitude = magnitude;
FirstDayOfWeek = DayOfWeek.Sunday;
}
