org-tr-regexp

org-tr-regexp is a variable defined in `org.el'.
Its value is

"<\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\} ?[^
\n>]*?\\)>--?-?<\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\} ?[^
\n>]*?\\)>"

• This variable may be risky if used as a file-local variable.

Documentation:
Regular expression matching a time stamp range.