People with shorter amounts of vacation time get really creative in maximizing their use. By leaving on the 19th (your example) and returning on the 27th they would only need to use 5 days of vacation time (assuming they also got the 24th as a vacation day). Saving the rest of the precious days for a summer trip or ??

The only really low traffic/low cost days are right on the holidays. I've booked trips flying on Dec 24/25 and returning Dec 31/Jan 1 for better prices. Sometimes you can see these lower rates ahead of time, but sometimes they only appear as last minute "sales".

Romelle