public static DateTime OffsetBy(this DateTime dt, int offsetVal, DateTimeOffsetStyles styles)
{
return(styles switch
{
DateTimeOffsetStyles.Day => DateTimeCalc.OffsetByDays(dt, offsetVal),
DateTimeOffsetStyles.Week => DateTimeCalc.OffsetByWeeks(dt, offsetVal),
DateTimeOffsetStyles.Month => DateTimeCalc.OffsetByMonths(dt, offsetVal, DateTimeOffsetOptions.Relatively),
DateTimeOffsetStyles.Quarters => DateTimeCalc.OffsetByQuarters(dt, offsetVal, DateTimeOffsetOptions.Relatively),
DateTimeOffsetStyles.Year => DateTimeCalc.OffsetByYears(dt, offsetVal, DateTimeOffsetOptions.Relatively),
_ => DateTimeCalc.OffsetByDays(dt, offsetVal)
});
public static DateTime AddQuarters(this DateTime dt, int quarters) => DateTimeCalc.OffsetByQuarters(dt, quarters);
