Hi. I've seen there are already some other bugs for this, but I also have a minimal code example for reproduction.

• node-cron 4.2.1
• Node 24.14.0

import cron from 'node-cron';
import Sinon from 'sinon';

Sinon.useFakeTimers(new Date('2026-03-31T09:00:01.000-02:00').getTime());

const job = cron.schedule('0 0 * * *', () => {}, { scheduled: false });

const nextRun = job.getNextRun();
console.log(nextRun);

Yesterday, the gextNextRun() gave the expected result, today in the morning it does not. Perhaps related to end of the month?