I used the below way to run the schedule on every two weeks on mondays.
ITrigger trigger = TriggerBuilder.Create()
.StartAt(DateBuilder.DateOf(StartHour, StartMinute, StartSeconds, StartDate, StartMonth, StartYear))
.WithCalendarIntervalSchedule(x => x.WithIntervalInWeeks(Int32.Parse(nWeekInterval)))
.EndAt(DateBuilder.DateOf(0, 0, 0, EndDay, EndMonth, EndYear))
.Build();
But how can I use a single schedule to run on mondays and tuesdays as well. Please advice.