Is it permissible for a fasting person to deliberately delay breaking their fast until the time of 'Ishā' (night prayer) or later?

It is disliked to delay breaking the fast after ascertaining that the sun has set if the fasting person believes that there is a virtue in doing so, because this contradicts the prophetic narrations. However, if one does not intend to seek virtue by delaying it, then there is no harm, as fasting is not valid at night.