Obviously, if I'm doing a calculation based on the circumstances, and those circumstances change, the outcome will change also.
Both this week and next week, for example, the Tesco shop has moved to Sunday, as I have a limited-time voucher that is good for £5 off my bill. Likewise, I will be attempting to handle the cleaning of the bathroom this Sunday, as Tuesday is Valentine's Day. (And while I could readily move it back to Wednesday, moving it forward to Sunday will make for a much more pleasant Tuesday, will it not?)
And, of course, after April anything and everything may change.