natural-cron

Natural Cron ⏰⏰

Natural Cron is a easy-to-use Node.js library for creating and validating cron expressions with natural, human-readable APIs.

Features

• Chainable methods for constructing cron expressions.
• Validation of cron components (minute, hour, day of the month, month, day of the week).
• Helpful error messages for invalid input.
• TypeScript support for strong typing and intellisense.

Installation

Install using npm:

npm install natural-cron

Or using yarn:

yarn add natural-cron

Usages

Utilize CronExpressionBuilder to generate cron expressions for various scheduling scenarios.

const { CronExpressionBuilder, CronValidators } = require('natural-cron');
const schedule = new  CronExpressionBuilder();

Using commonly used predefined cron expressions

const { SCHEDULES } = require('natural-cron');
const exp1 = SCHEDULES.EVERY_30_SECONDS;
const exp2 = SCHEDULES.EVERY_2ND_HOUR_FROM_1AM_THROUGH_11PM;

📋 Examples Table

📅 Description	💻 Code Example	⏰ Cron Expression
Run a job at 5:30 PM every day	schedule.atTime('17:30').compile();	30 17 * * *
Run at 9 AM on weekdays	schedule.atTime('09:00').onWeekDays([1,2,3,4,5]).compile();	0 9 * * 1-5
Run at noon on the 1st and 15th of the month	schedule.atTime('12:00').onDaysOfMonth([1, 15]).compile();	0 12 1,15 * *
Run at midnight during January and July	schedule.atTime('00:00').duringMonths([1, 7]).compile();	0 0 * 1,7 *
Run every 15 minutes	schedule.everyX(15, CronTimeUnit.Minute).compile();	*/15 * * * *
Run every day at noon	schedule.every('day').atHours([12]).compile();	0 12 * * *
Run every Sunday at 5 PM	schedule.onWeekDays([0]).atHours([17]).compile();	0 17 * * 0
Run the 1st day of every month at 1 AM	schedule.onDaysOfMonth([1]).every('month').atHours([1]).compile();	0 1 1 * *
Run every weekday at 8:30 AM	schedule.atTime("08:30").onWeekDays([1, 2, 3, 4, 5]).compile();	30 8 * * 1-5
Run every 6 hours	schedule.everyX(6, CronTimeUnit.Hour).compile();	0 */6 * * *
Run every quarter at midnight	schedule.duringMonths([1, 4, 7, 10]).onDaysOfMonth([1]).atTime("00:00").compile();	0 0 1 1,4,7,10 *
Run every Saturday and Sunday at 10:15 AM	schedule.atTime("10:15").onWeekDays([6, 0]).compile();	15 10 * * 6,0
Run at 9 AM, 12 PM, and 3 PM every day	schedule.every('day').atHours([9, 12, 15]).compile();	0 9,12,15 * * *
Run at 7 AM, 2 PM, and 10 PM on Tuesdays	schedule.atHours([7, 14, 22]).onWeekDays([2]).compile();	0 7,14,22 * * 2
Run at 20 past every hour on the 5th of July	schedule.atMinutes([20]).onDaysOfMonth([5]).duringMonths([7]).compile();	20 * 5 7 *
Run every 5 minutes during office hours - every()	schedule.every('minute').atMinutes([0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55]).atHours([9, 10, 11, 12, 13, 14, 15, 16]).compile();	0,5,10,15,20,25,30,35,40,45,50,55 9-16 * * *
Run every 5 minutes during office hours - everyX()	schedule.everyX(5,CronTimeUnit.Minute).atHours([9, 10, 11, 12, 13, 14, 15, 16]).compile()	*/5 9-16 * * *
Run at quarter past and quarter to every hour	schedule.every('hour').atMinutes([15, 45]).compile();	15,45 * * * *

Note: schedule is an instance of CronExpressionBuilder utilized for generating the cron expressions.

API Reference

CronExpressionBuilder

• atMinutes(minutes: Array<number>): this
• atHours(hours: Array<number>): this
• atTime(time: string): this
• every(unit: string): this
• everyX(interval: number, unit: ScheduleUnit): this
• onWeekdays(days: Array<number>): this
• onDaysOfMonth(days: Array<number>): this
• duringMonths(months: Array<number>): this
• compile(): string - Get the cron expression

Use CronTimeUnit enum for ScheduleUnit

export enum CronTimeUnit {
  Minute = 'minute',
  Hour = 'hour',
  DayOfMonth = 'dayOfMonth',
  Month = 'month',
  DayOfWeek = 'dayOfWeek',
}

CronValidators

Static methods for validating cron expression components.

• validateMinute(minute: number)
• validateHour(hour: number)
• validateDayOfMonth(day: number)
• validateMonth(month: number)
• validateDayOfWeek(day: number)
• validateTime(time: string)

Contributing

Contributions are welcome! Please feel free to submit a pull request.

License

This project is licensed under the MIT License.