Reviewing

Stella schedules cards with a Go port of Mnemosyne’s SM2 algorithm. After each card you grade how well you remembered it, from 0 (blackout) to 5 (perfect recall), and the grade sets when you see the card next: well-remembered cards come back at ever longer intervals, forgotten ones come back soon.

Settings

The review section of the config tunes the scheduler:

SettingDefaultWhat it does
dayStartsAt3Hour (0-23) at which a new study day begins, so a late-night session still counts for the day before
nonMemorisedCardsInHand10How many not-yet-retained cards are juggled at once
maxScheduledIntervalDays0Cap on the scheduled interval in days; 0 means no cap
randomiseScheduledCardsfalseShuffle due cards instead of ordering them by interval
randomiseNewCardsfalseShuffle the order in which unseen cards are introduced

Day boundaries use the top-level timezone setting (an IANA name such as Europe/Madrid), or the host’s local timezone when it is empty.