What was the witching hour in The BFG?

Answer 1

The Witching Hour is another term for midnight.

It goes back to older superstitions concerning a time when witchcraft and other supernatural occurrences went on. It was first coined in 1835.

Ex: We'll be out passed the Witching Hour.

I believe it more closely refers to the time between midnight and 3:am. Obviously it stemmed from the time when witchcraft was a common belief. It was the time of night when spirits, demons, and witches were at their strongest. Midnight being the opposite of noon, creates an axis which links the mundane world to the spirit world, thus why black magic is stronger at midnight. After going beyond 3:am, the connection starts to weaken as it nears dawn.

The phrase "The witching hour" was actually first seen in the 1831 edition of Frankenstein in Mary's introduction. Though it was seen later in 1835 in a short story written by Washington Irving. However, the concept of the witching hour goes as far back as Shakespeare in Hamlet phrased as "The witching time of night."
The witching hour is a time of night when supernatural creatures are believed to be particularly active, making it a prime time of night for witchcraft. Many people think of midnight specifically as the witching hour, while others more generally associate it with the dead of night, the dark hours when few people are awake and about. The association of darkness and supernatural activity is quite ancient, although the term "the witching hour" itself only dates back to around the early 1800s; terms like "the witching time of night" were used prior to this period.

Answer 2

In Roald Dahl's "The BFG", the witching hour is the time at night when witches and other supernatural creatures are believed to be active. It's a time of darkness and mystery that adds to the atmosphere of the story.