Super simple job scheduler for TypeScript/JavaScript

job.ts

export function job(time: number | string, job: Function): number {
	let millis: number;

	if (typeof time === 'number') {
		millis = time;
	} else {
		if (!isNaN(time)) {
			millis = parseInt(time);
		} else {
			const num = parseInt(time.slice(0, -1));
			const unit = time.substr(-1);

			if (unit === 's') {
				millis = num * 1000;
			} else if (unit === 'm') {
				millis = num * 60 * 1000;
			} else if (unit === 'h') {
				millis = num * 60 * 60 * 1000;
			} else {
				millis = num;
			}
		}
	}

	return setInterval(job, millis);
}