Oh, the Ambiguity!
For Walk around the Block Day, I'm sure the first thing you thought of was going out and physically walking around a city block composed of two pairs of parallel, intersecting streets, right?
Well, that of course is the obvious intent of this day, but wait! There's more!
You might instead choose to find a small block of wood or plastic, such as would be part of a child's toy, and take a few steps around it.
On the other hand, if you're ambitious and don't have a standard city block in your neighborhood, you could walk in a circuitous route from your starting point and back again. That might involve something more like a country mile than a city block.
I don't think there's a non-physical way to get around this one.
If you want to go the other way around the block, that's fine. Generally I take that to mean only going half way around a block, but you probably have to come back again, or you went one way around the block on your way out and are now coming back the other way, which may or may not be longer than the first way, but in the end in takes you all the way around the block which is the whole point of today's exercise, so you should be okay there.