Well, it's a common failure mode, you should figure out some way of signalling that you don't fall in it (and I should learn to ask the right questions). Since you can change your mind about what to do at 11AM, it's appealing to think that you can also change the fact of the matter of what happens at 11AM. To avoid such confusion, it's natural enough to think about "the algorithm you implement at 10AM" and "the algorithm you implement at 11AM" as unrelated facts that don't change (but depend and are controlled by particular systems, such as your source code at given time, or even "acausally", or "logically" controlled by the algorithms in terms of which they are defined).