There a couple of rules about the positioning of characters within the class but, generally, if it is not the first character then it doesn't require escaping.
I just thought I would mention this For anyone interested: In most regex flavors, the only special characters or metacharacters inside a character class are the closing bracket (]), the backslash (\), the caret (^), and the hyphen (-).
You can include an unescaped closing bracket by placing it right after the opening bracket, or right after the negating caret. [^]x] matches any character that is not a closing bracket or an x.
So with these flavors, you can't escape anything in character classes.
To include an unescaped caret as a literal, place it anywhere except right after the opening bracket. This works with all flavors discussed in this tutorial.
The hyphen can be included right after the opening bracket, or right before the closing bracket, or right after the negating caret. [^-x] and [^x-] match any character thas is not an x or a hyphen.
For example, 41/01/2001 is not a real date, despite it being in the correct format.Is it a string/text column you wish to validate matches that pattern? Do you wish to make it a string/text for output, do you wish to make it a Date format?