aws-cron-parser/README.md

A util to parse cron expressions used by AWS services

# AWS Cron Parser

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This utility was built to process AWS Cron Expressions used by Amazon CloudWatch. It can support all the specs listed in the link below, including the special wildcards L W and #.

## Specs

[AWS Cron Expression specs](https://docs.aws.amazon.com/AmazonCloudWatch/latest/events/ScheduledEvents.html#CronExpressions)

## Installation

```sh
npm install aws-cron-parser
```

## Usage

There are only 3 methods: `parse`, `next`, and `prev`

```js
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);
```