وَإِنْ كَانَ أَقَلَّ مِنْ ذَلِكَ فَعَلَيْهِ صَدَقَةٌ
Translation: If the duration is less than that, charity is due.
The demonstrative dhalika refers back to the full duration. In the ordinary textbook contrast, if a male muhrim wears the prohibited garment for only part of the stipulated day, the text prescribes sadaqah.
Both duration and the nature of the garment matter. The presence of a stitch in an object is not by itself enough to decide the legal ruling.