Mine has taken 3-4 days on average and they have always dropped it off after 11pm.
One time it was almost 1am and they were so loud they woke my neighbours too.
Every time the courier says "because of London traffic" or "we don't have a gps" when they get lost
Honestly if it's on the next plane it's usually best to just wait and then complain about the delay for some avios lol