Actually, it’s a flag for any non-leap year that begins on a Thursday. The boundaries aren’t shown, but it’s made from 53 narrow columns (weeks, running from the first week on the hoist edge to the last week on the fly edge) and 7 wide rows (days of the week, with Sunday along the top and Saturday along the bottom). In other words, it’s a calendar turned into a flag. It’s a bit hard to read as a calendar since the order of days goes top to bottom, and then left to right — but that’s the logic of flags, not the logic of text!
Portland Flag Association 