When I was a transport consultant, in a former life, I noticed something that might be of interest to Bah Humbug types.
I realised that the Department for Transport regularly published Invitations To Tender in early-mid December, with bids due in early January. This inevitably meant that the bid teams couldn't take much time off over the Christmas / New Year period.
(It wasn't just Christmas though. I dug through the records and discovered that the DfT issued disproportionate numbers of ITTs around March, with bids in immediately after Easter, and at the end of July, with bids due in early September.)
I brought this up at a Steering Group meeting and they admitted that yes, it was a deliberate policy. Evaluating bids was a difficult job and they found that their staff could do it more effectively just after a significant break such as Christmas, Easter, or the summer holidays. It had honestly not occurred to them that an inevitable consequence of their policy was that they were consistently and repeatedly stuffing up the holiday plans of all their contractors.