When you play along on your own piano, none of your playing reaches the app. So the practice log here does not score you; it keeps three things - the time you practised, what you worked on and how you felt it went. It is a record for keeping going, so it asks as little effort as possible.
What is recorded, and when
Play a piece on its song page and the practice timer switches to Recording, counting only the time the piece is playing (in practice mode, where the piece waits for you, it keeps counting as long as you have moved the piece on within the last 60 seconds). It runs on the audio clock, so time with the computer asleep is not counted. Anything under 30 seconds cannot be recorded; past that, "Record this practice" becomes available, and reaching the end of the piece also asks "Record this practice?".
Leave the page without recording and the time is saved anyway, listed as "Details missing" for you to fill in later. For a MIDI file of your own, or practice away from the screen, use the practice stopwatch on the Practice page, or Add a record and type the minutes (1 to 600). What you practised can be a piece from the site or anything you type: Hanon, scales, a lesson.
Recording what you did and how it went
"What you worked on" comes pre-selected from how the piece was played: Slow if the speed went below 1x, Section if you used the loop, Full run if playback reached the end (unless you also used the loop, in which case Section is chosen instead), Practice mode if you used it. Correct anything wrong, and add Right hand, Left hand, Memorising and so on. A record marked Listening only does not count towards practice time, streaks or goals.
"How it went" has three levels: Still hard, Mostly played it, Played it. Three Played it ratings in a row make the piece Playable; if those three span at least 14 days, it becomes Settled - the difference between a piece that went well one day and one you can still play after a fortnight. The note field takes up to 200 characters of anything you noticed.
How days and streaks are counted
A practice day ends at 4am rather than midnight, so a late session that runs past twelve still counts towards that evening. You can change the hour under "A day starts at" in the settings, and choose whether the week starts on Monday or Sunday.
Days in a row allows one missed day a week. The missed day is not added to the count, but the streak carries on, with the note "One rest day is holding the streak" - so a week where you cannot play every day does not send it back to zero at the first gap. Switch this with "Allow one rest day a week". And a day you have not practised yet does not break the streak until the day is over.
Goals are optional: days per week, minutes per day, minutes per week, each set or left alone. The practice calendar and the "Last week" review show your time week by week, the pieces you practised most and those whose ratings went up.
Making sure the log survives
The log is stored in this browser only and is never sent to a server. Clearing the site's data, or using a private window, leaves nothing behind, and another browser or computer cannot see it.
So export now and then with "Export (JSON)" under Your data. The file holds your records together with My pieces and your settings. Once more than 30 days of records have gone unexported, a reminder appears.
To move to another browser, open that file with Import there. "Add to what is here" keeps every existing record and adds only the new ones - the same record is never counted twice. "Replace everything" swaps the current log for the file's contents.