Lost stats for a random day in the past

[ankianki99]

AnkiDroid Version = 2.20.1 (e32a82c33646807ea19623c9c88be38965bc07e6)

Backend Version = 0.1.48-anki24.11 (24.11 c47638ca36f99dd4f3b81ae82d964aec66e392e0)

Android Version = 14 (SDK 34)

ProductFlavor = play

Manufacturer = samsung

Model = SM-S911B

Hardware = qcom

Webview User Agent = Mozilla/5.0 (Linux; Android 14; SM-S911B Build/UP1A.231005.007; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/134.0.6998.108 Mobile Safari/537.36

ACRA UUID = 3e89b172-f055-48cb-8986-5fb30197be8b

FSRS = 1.4.3 (Enabled: true)

Crash Reports Enabled = true

Today I decided to check my stats for the full lifetime of one deck and, to my surprise, a gap had appeared.

Data for a date 43 days ago is no longer there. I had a perfect streak up until now, and I have looked at these stats almost daily (including the full range when it shows more than a month’s worth of data).

Weirdly, 2 days ago it was normal (second screenshot).

I also noticed, a couple days ago, that my mature count had lowered by one card even though I have not gotten a mature card wrong in over a month.

The only different thing I have done is that I experimented with creating a few review decks the past couple of days. I have also edited a couple cards (just the definition of a few words).

I don’t know the intricacies of Anki so I’m just reporting what I have done outside the usual routine of doing my reviews.

I made a backup of day 21 (I had not synced my Linux Anki yet so the gap wasn’t present there) just in case it is possible to merge stats data somehow…

I would really like to recover my stats to completion, and also avoid this from happening in the future. So I would appreciate any insight.

[Danika_Dakika]

@ankianki99

Data for a date 43 days ago is no longer there.

If you compare those 2 graphs closely, you can see that spike the day before the gap actually used to be split between those 2 days.

• Did you change your next-day-starts time? Preferences - Anki Manual
• Are in a different time zone than a few days ago?
• Did your time zone have a seasonal time change?

@ankianki99

my mature count had lowered by one card even though I have not gotten a mature card wrong in over a month

Your number of Mature cards isn’t something magical – it’s just how many cards have an interval of 21+ days. If anything causes one of those cards to have a shorter interval, it will stop being “Mature” for now.

It looks like you’re using FSRS. Did you reoptimize and reschedule cards recently? Have you used “Set Due Date” to manually reschedule any of your cards?

[ankianki99]

@Danika_Dakika

If you compare those 2 graphs closely, you can see that spike the day before the gap actually used to be split between those 2 days.

• Did you change your next-day-starts time?

Oh! Very keen eye!

Yes! I changed my next-day-starts time TODAY! I pushed it from 4am to 6am.

I reverted it back to 4am and now my streak is complete!

Thank you so, so much!

[Danika_Dakika]

You’re quick! I was just editing to add a response on your other question.

[ankianki99]

@Danika_Dakika

Your number of Mature cards isn’t something magical – it’s just how many cards have an interval of 21+ days. If anything causes one of those cards to have a shorter interval, it will stop being “Mature” for now.

What got me confused is that I didn’t make any mistakes on mature cards so I don’t understand why the total number of them would drop. I’m pretty sure I had 71 mature cards a few days ago and was following that number because it started bugging me that “number not going up”. But maybe I’m misremembering.

@Danika_Dakika

Did you reoptimize and reschedule cards recently?

Hm, I don’t think I have re-optimized but frankly I don’t remember. This might have been it.

I have not manually rescheduled cards.

Thanks again for your help! The mature card thing is a minor issue I was just curious what had happened. Having the perfect streak is more important for my motivation and OCD