Fix/don't reschedule to the past when today is easy day

[L-M-Sherlock]

No description provided.

[user1823]

Why do we need allow_to_past to be True in some cases? Shouldn't it always be False?

My reasoning:
If the latest possible due date is in the past, the load balancing is skipped. So, allow_to_past is used only for those cards that have some possible due dates in the future. Moving such cards to the past doesn't make sense because the user can't do them in the past.

(If the latest possible due date is in the past, rescheduling to the past still makes some sense because the card is beyond its due range now.)

[L-M-Sherlock]

Why do we need allow_to_past to be True in some cases? Shouldn't it always be False?

For example, the user increases the desired retention.

[user1823]

But in that case, the following code will make the card due in the past.

fsrs4anki-helper/schedule/reschedule.py

Lines 91 to 93 in 4f1d969

	if due - self.card.ivl + max_ivl <= mw.col.sched.today:
	# If the latest possible due date is in the past, skip load balance
	return ivl

[L-M-Sherlock]

But in that case, the following code will make the card due in the past.

It's intended. The load balance also tries to balance the backlog and the future workload.

[user1823]

I am not saying that those cards should not be scheduled in the past.

I am saying that this code (line 91-93) is enough to ensure that the cards are scheduled in the past when the user increases the desired retention (or updates the parameters). So, you don't need to set allow_to_past to True.

[L-M-Sherlock]

But it doesn't affect those cards whose fuzz ranges include today.

[user1823]

Yes, but what benefit do you get by scheduling a card yesterday (or any other past day) instead of today?

I mean, if the fuzz ranges allows scheduling the card today, why not schedule it today?

Edit:
Do you mean that I should remove the = sign from that code so that it becomes this?

 if due - self.card.ivl + max_ivl < mw.col.sched.today: 
     # If the latest possible due date is in the past, skip load balance 
     return ivl 

[L-M-Sherlock]

It makes the future due graph looks smoother because the cards due in yesterday are included in the backlog which is hidden by default.

[user1823]

With the current load balancer, the graph will NOT look smooth when there is a backlog.

Reason:
Today's workload includes the backlog but tomorrow's workload doesn't.

fsrs4anki-helper/schedule/reschedule.py

Lines 134 to 138 in 4f1d969

	# If the due date is in the future, the workload is the number of cards due on that day
	workload = self.due_cnt_per_day[check_due]
	else:
	# If the due date is in the past or today, the workload is the number of cards due today plus the number of cards learned today
	workload = self.due_today + self.reviewed_today

fsrs4anki-helper/schedule/reschedule.py

Lines 61 to 65 in 4f1d969

	self.due_today = sum(
	due_cnt
	for due, due_cnt in self.due_cnt_per_day.items()
	if due <= mw.col.sched.today
	)

So, with the current code, after load balancing, today's due count in the Future Due graph will lesser than tomorrow's because today's due count doesn't include the backlog.

If the cards are scheduled today instead of the past (like in my PR), they will be included in today's due count so the graph will be more smooth.

[user1823]

Proof:
In the screenshots below, see how the current code makes the today's due count 0 in the Future Due Graph.

Current code:

My code:

[L-M-Sherlock]

OK. I will check the PR tonight.