Next occurrences of a cron expression in any IANA time zone, DST-aware via the runtime's ICU tzdb (times skipped by DST shift forward by the gap; ambiguous times fire once). Dialect (croner): 5-7 fields with optional seconds and year, ranges, steps, lists, JAN-DEC/SUN-SAT names, L, W, #, ? and @daily-style aliases. Each occurrence is returned as local ISO with offset plus UTC. Bad expression → 400 naming the offending field.