[3.14] Datetime: Tidy up docs (GH-144720) (GH-144956)

(cherry picked from commit c6a142f9472f2d3e2c360b72a19450f9dd087657)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com>