Is it reprehensible to fast on a Friday if you intended to fast on Thursday of Shawwal but did not complete it, and then fasted Friday alone without singling it out?

It is disliked to single out Friday for fasting unless it coincides with a fast that a person habitually observes, or if there is a specific reason for it, such as fasting a day before or after it, or if it coincides with a day whose fasting is recommended, like 'Arafah and 'Ashura', or if it is for making up a missed fast and one was unable to fast it on another day. And whoever fasts on Friday with the intention of fasting Saturday but is prevented by an excuse, then there is no harm in his fast.