  We deal with the De Giorgi H{\"o}lder regularity theory for parabolic
equations with rough coefficients and parabolic De Giorgi classes which extend
the notion of solution. We give a quantitative proof of the interior H{\"o}lder
regularity estimate for both using De Giorgi method. Recently, the De Giorgi
method initially introduced for elliptic equation has been extended to
parabolic equation in a non quantitative way. Here we extend the method to the
parabolic De Giorgi classes in a quantitative way. To this aim, we get a
quantitative version of the non quantitative step of the method, the parabolic
intermediate value lemma, one of the two main tools of the De Giorgi method
sometimes called ``second lemma of De Giorgi''.
