import awsCronParser from "aws-cron-parser";

// first we need to parse the cron expression
const cron = awsCronParser.parse("9 * 7,9,11 5 ? 2020,2022,2024-2099");

// to get the first occurrence from now
let occurrence = awsCronParser.next(cron, new Date());

// to get the next occurrence following the previous one
occurrence = awsCronParser.next(cron, occurrence);

// and use prev to get the previous occurrence
occurrence = awsCronParser.prev(cron, occurrence);