DecksWhy Anki's day starts at 4am, and when to change it
Anki's study day starts at 4am by default, not midnight. That way, if you're studying around midnight, you don't get two days of cards in one sitting. Cards with intervals measured in days become due at the start of their day, so a card scheduled for "1 day" is due from 4am tomorrow, not 24 hours after you answered it. You can change the hour in Anki's preferences, under Review, with the Next day starts at setting.
What it changes
- When today's cards appear. At 4am the new day's reviews and new cards become available.
- What "1 day" means. Day-length intervals count study days, not hours. Answer a card at 11pm with a 1-day interval and it's due from 4am, five hours later, not at 11pm the next night.
- Learning steps that cross the boundary. A step that lands past the start of the next day is converted to days and shows up at the start of that day, like a review.
The time follows your current time zone, so if you travel, the day starts at 4am wherever you are.
When to change it
Set it to an hour when you're usually asleep.
| You usually study | Good setting |
|---|---|
| Daytime and evening, in bed by 2am | 4am (default) |
| Late, often until 4 or 5am | 6am or later |
| Night shifts or odd hours | The middle of your usual sleep |
If you study past the boundary, the cards you see belong to the next day, and you'll find fewer waiting when you sit down later that day.
Why cards seem to come back "early"
People sometimes see a 1-day card again only a few hours after they rated it, and think the scheduler is wrong. It's this rule: the card's day began at 4am. The same applies at longer intervals; a 3-day card is due from the start of the third day. Why does the same flashcard keep coming back covers the other common causes.
The learn ahead limit
A related setting in the same place: when you've finished everything except cards on short learning steps, Anki shows those up to 20 minutes early instead of making you wait. Set it to 0 if you'd rather always wait for the full step. Anki learning steps explains the steps themselves.
In Decks
Decks uses the same 4am rule: day-length intervals are counted in study days that start at 4am local time, so a card that's due tomorrow is due all day tomorrow. Decks also shows learning cards up to 20 minutes early when nothing else is left. Neither setting can be changed in Decks.
Published 2026-10-19.