What would be the advantage of using that rather than (localtime ($date))[6]? The only differences I see, based on the Date::Manip docs, seem to be whether the date is specified in epoch seconds or as m/d/y and whether Sunday is considered to be day 0 or day 7.

If there is an advantage, I can definitely switch, but I personally prefer to handle dates internally as epoch times and, in this case, to use localtime to get the day of week directly from that value rather than converting the epoch time to m/d/y so that m/d/y can be given to Date_DayOfWeek. I suppose I don't want to change it without knowing why I'm changing it.