What is "1 day"?

WaniKani Feedback
1

OK, this may be slightly philosophical but… what is “1 day” in WaniKani SRS (WaniKani’s SRS Stages | WaniKani Knowledge)?

Apprentice 3 → 1 day → Apprentice 4
Apprentice 4 → 1 day → Guru 1 (earlier levels)

I’m asking because I adopted particular schedule (to have more predictable study times):

  • do new lessons at 8:00am in the morning
  • do all reviews at 12:00 (noon, after ~4h so new items are included)
  • do new items review using self-study-quiz in the evening, doesn’t affect review schedule.

Considering that I should have rather consisted pile of reviews around 12:00 each day but, after weeks with this schedule, each day this pile falls on 11:00 (which would look like “1 day” = 23 hours :D):

Screenshot 2026-05-15 at 08.40.27
Screenshot 2026-05-15 at 08.40.27790×592 45.7 KB

(the 5 items at noon are new items I just studied at 8:00 in the morning)

It’s not a big issue because I just let them slide to my study window at noon, but it made me very curious why it’s happening :smiley: Seems a bit like a very popular “off by 1” programmer issue :smiley:

2

It’s not like that just for 1 day interval, the pattern just starts at 1 day. The shorter intervals are exactly as advertised. The longer ones are the advertised interval -1 hour.
Personally I’ve always seen it as a good feature. If I do the reviews at regular times (the same approach you use, just different times), it gives me a bit of a buffer. If I have a bigger pile or if I start later in that hour and some reviews slip into the next hour, I still get the future reviews in my usual hour. It’s simply a small buffer - better user experience.

3

1 day is treated as 23 hours to give some buffer for people who do their reviews at the same time every day to prevent their review time slowly shifting around the day if they’re not exactly on time

4

hmm… this actually is… smart and convenient :smiley: (and indeed I do appreciate it :wink: ).