I ran into the same issue. FluentScheduler isn't robust enough to handle very complex schedules. A better solution would be to use http://www.quartz-scheduler.net/ It is very flexible, is supported by Topshelf, and has support for most IoC containers.
For example in my service I used:
config.Service<Service>(sc =>
{ sc.ScheduleQuartzJob(configurator =>
configurator.WithJob(
() => JobBuilder.Create<DataLoadJob>().WithIdentity("DataLoad", "Job1").Build())
.AddTrigger(() => TriggerBuilder.Create().WithIdentity("DataLoadSchedule", "Job1")
.WithSimpleSchedule(builder => builder.WithIntervalInSeconds(10).RepeatForever()).Build()));
sc.ScheduleQuartzJob(configurator =>
configurator.WithJob(
() => JobBuilder.Create<DataMergeJob>().WithIdentity("DataMerge", "Job1").Build())
.AddTrigger(() => TriggerBuilder.Create().WithIdentity("DataMergeSchedule", "Job1")
.WithCronSchedule("0 30 7-20/3 ? * MON-FRI").Build()));
sc.ConstructUsingSimpleInjector();
sc.WhenStarted((s, h) => s.Start(h));
sc.WhenStopped((s, h) => s.Stop(h));
});
This is a fragment from a Topshelf service using SimpleInjector along with Quartz.