I have my own quota wherein I should spend about 8 to 12 hours a day,but thanks to school during weekdays,I only play an hour or two. I go all out playing during weekends and holidays though. And within those hours; 50% of the time playing, 40% doing something else ,5% listening to music and 5% when spectating random people out of boredom.
Warning maths incoming. (This works for ME, and these calculations may not work for you)
To begin with say that I play 2 hours every day (same days more then others so this is an average) and on weekends say 4 hours every day. Take in mind weekends and normal days, as I am a student I have two day breaks, and less time on school days.
So an average week is around 18 hours out of 168 hours in a week. Now I add holidays. I will just call a holiday day as a weekend as its the same thing hour wise. I will use my school calendar to calculate this (nice try, you 'aint 'getting this link). I shall start from January 1st.
In total in one school year I have: Summer Holidays/Spring Break Holiday Days (+weekends): 12 + 19 + 10 + 13 + 15 + 8 + 16 + 31 + 9 + 14 + 9 + 17 = 173 Holidays Days School Days: 20 + 9 + 25 + 17 + 15 + 27 + 15 + 0 + 21 + 16 + 14 + 14 = 193 School Days
On a side-note, 173 + 193 = 366 (nailed it, first try)
SO, if there are no variations in my schedule, 193 School Days * 2 Hours = 386 Hours. 173 School Days * 4 Hours = 692 Hours.
386 Hours + 692 Hours = 1078 Hours.
I have played Osu! for exactly one year, this means I have put 1078 hours in to this amazing game.