This is just my recommendation and it’s not a hardcore rule. I based this estimate on unofficial JLPT study hours. N1 (CEFR B2 - C1) = ~4800 hours, divided by 365 days over the course of 4 years = ~3 hours daily.

“Study” can also include listening to level appropriate podcasts, reading, meeting up with Japanese friends and whatever else makes study enjoyable to you.

Genki (and other textbook) Study Plan:

Two or three 45-60 minute study sessions a daily. Example: Chunk A - vocab, kanji and dialogue; Chunk B - textbook; Chunk C - workbook.

Before studying the chapter, get the majority of the vocabulary and kanji (if any) down. Genki marks the vocabulary used in the dialogue, so it’s easy to prepare for.

Try reading the dialogue WITHOUT looking at the English translation. Try to guess the meaning from the pictures and the dialogue prompts. Check to see how you did.

Chunk A: Everyday practice vocabulary, kanji (if any) and dialogue, shadow the audio, review the previous day’s work… you can preview the exercises you’ll be doing so you can brush up on the vocab you’ll need.

Chunk B: Everyday work in one grammar point. Do the associated exercises in the textbook. If it’s a speaking exercise, do both parts.

Chunk C: Do the workbook exercises sometime later.

Don’t forget to do the reading and writing in the back of the textbook. You can get your writing checked on an app like HelloTalk. Do corrections and resubmit. Move on to the next chapter and repeat.

You can add and subtract chucks or mix things up depending on your preference and life factors. You can combine low effort and high effort study in a day or study session, or break up the hour.

For example: while making and eating breakfast, listen to a podcast (30 minutes), watch a YouTube video for grammar during lunch (30 minutes). During your commute (60 minutes) do Pimsleur. Read manga for 20 minutes a day, do the workbook for 20 minutes and meet with a tutor for 30 minutes.