utilpeek: Build an iCalendar file from JSON events. Returns 1-50 events (summary, start, end or duration, IANA timezone, all-day, location, description, url, organizer, attendees, rrule, uid) turned into RFC 5545 VCALENDAR text: CRLF lines folded at 75 octets, text escaped (commas, semicolons, backslashes, newlines). Returns the ics text, its base64 and a data: URI, with the uids. Input: events, optional calendar_name, default timezone and time_format. Pure computation: no network access, nothing stored. A zoned start is written as TZID= with no VTIMEZONE block; an offset becomes UTC; a plain local time stays floating. All-day end is the last day, inclusive. A bad time zone, date, rrule, email or url, or both end and duration, is a 422 naming the event (not charged). Typically under 0.1 s. Price: USD 0.001. Free: 10 utilpeek calls per IP per UTC day. Docs: https://tanod.dev/learn/ics-calendar-api.html