It is nine p.m. Today I got up this morning at around 8:30 so I have been awake for at least 12 hours. But I have done very little, or better almost nothing. It is true that I offered two lessons today, each of which was 1.5 hours, so they are 3 hours in total. However, how were the remnant nine hours wasted? I remember taking 2 hours before the lessons, so it leaves 7 hours for me, no it should have left 7 hours for me. Where are they gone? Now I remember. After getting home from work, I was so tired that I slept for about an hour. That couldn't be helped. Nevertheless, it follows that I wasted 6 hours today, letting them pass me by. I think I will have to maintain a record how I spend or waste my time. Do you know any useful apps for it? If you do, please let me know.