// rhythm-cycle-30hr.el — rhythm_cycle_phase(0.5) under CycleCalendar(30.hours)
// returns the next instant at the 15-hour mark of the cycle.

fn run_test() -> Int {
    let period: Duration = 30.hours
    let cal: Calendar = cycle_calendar(period)
    let r: Rhythm = rhythm_cycle_phase(0.5)
    let base: Instant = unix_seconds(0)
    let next: Instant = rhythm_next_after(r, base, cal)
    let elapsed_ns: Duration = next - base
    let elapsed_secs: Int = duration_to_seconds(elapsed_ns)
    // 15 hours = 54000 seconds.
    return elapsed_secs
}

fn main() -> Void {
    println(int_to_str(run_test()))
}