The IRS is supposed to open up and begin processing 2024 returns sometime today, Monday, January 27, 2025. They will have a large backlog as they start to pull returns from various preparers. Normally once they start processing, people will receive their accepted/rejected notice within 24-48 hours, but sometimes sooner.
You may see in this forum that a few people have already been accepted/rejected. That's because the IRS pulls a few returns early for testing purposes. The vast majority of people who have already efiled have returns sitting in a queue that the IRS will start to access today when they begin processing.