Winter weather of the sort we've been having of late, grey and damp, is often described as dismal, but to astrologers the word means something more than just cold and wet. The word 'dismal' comes from two Latin words, 'dies mala', which means 'unlucky day', and in times gone by it was used to refer to a specific number of dates which were supposedly ill-omened. The original string of dates is at least two thousand years old and originated in Egypt, though the precise reasons for them are no longer known. I'm not sure I go along with superstitions where you don't know why you're doing it: I reckon that when it gets to that stage there's not much magic left in it. For what it's worth, though, this Sunday is the next dismal day, which gives you a good excuse for not doing anything much; and, to counteract that, next Tuesday is a day for increasing your fortune, so if you buy or sell anything on that day you'll make a profit. The old books don't say anything specific about Lotto tickets, but they probably come under 'increasing fortune' somewhere.
To old astrologers negotiating the calendar must have been like stepping through a minefield: not only are there good days and bad days, but days with potholes in them, when 'a man cast into a ditch cannot easily get out without help' (which sounds like the roads around where I live) and even so-called 'smoky' days, which sound rather interesting to me, and conjure up images of some sort of celestial speakeasy, where planets do deals in the dark. Maybe it's just my active imagination!