仕事が入ってしまった為、今度のレッスンの日にちを変更してください。
13日が希望です。時間は何時でも大丈夫です。
いつも申し訳ございません。
I'd like to re-schedule our next lesson since I can't make it due to my work schedule.
The 13th is preferable, at any hour.
I hope it won't be too much a problem for you. Thank you very much, as always.
