Which oath should be adopted from the following two oaths: an oath not to do something for a week, and an oath to do the same thing in the middle of the week? And is expiation required if the thing is done in the middle of the week?

It is not permissible to be complacent with an oath by Allah, and oaths must be safeguarded by not making excessive use of them except out of necessity. One must avoid making Allah an object of frequent oaths. If one swears an oath to do something, and then sees that something else is better, then he should expiate for his oath and do what is good, because the first oath is not annulled by a second oath. Swearing two contradictory oaths definitely necessitates expiation.