func (crnI *CronInstance) nextS(inc bool) bool {
    fromS := crnI.s
    crnI.s, _ = next(crnI.crn.seconds, fromS, inc)
    if crnI.nextMin(crnI.s > fromS || inc && crnI.s == fromS) {
        crnI.s, _ = next(crnI.crn.seconds, 0, true)