In
ll. 47-50 Van Gogh says that he will start painting the next Monday. Given that on Sunday, 20 August 1882 he writes that he has then been painting for about two weeks (
see letter 258), the Monday he is referring to must be 7 August, and the present letter must date from a few days earlier. Moreover, the letter follows
letter 253 of Saturday, 5 August, because Van Gogh returns to the subject of the perspective frame (
ll. 2 ff.). So the letter can only have been written later on the same Saturday, 5 or on Sunday, 6 August 1882.