Although Jewish weddings may take place on the days in between the Jewish High Holidays, it is generally discouraged because during that period, also known as the Days of Awe, we are focused on the solemn themes of the season.
The blessing after the reading of haftarah always sanctifies the day on which it is read. Throughout most of the year, that day is Shabbat, but haftarah is also read on the High Holidays.
The High Holidays are a time of introspection and self-assessment in anticipation of repentance, forgiveness, thanksgiving and rejoicing. It is a season of healing.