mh-scan-date-regexp

mh-scan-date-regexp is a variable defined in `mh-scan.el'.
Its value is

"\\([0-9][0-9]/[0-9][0-9]\\)"

Documentation:
This regular expression matches a valid date.

It must not be anchored to the beginning or the end of the line.
Note that the default setting of `mh-folder-font-lock-keywords'
expects this expression to contain only one parenthesized
expression which matches the date field as in the default of
"\\([0-9][0-9]/[0-9][0-9]\\)"}. If this regular expression
is not correct, the date will not be highlighted with the face
`mh-folder-date'.