4 ms·

The difference of sun to the noon is at maximum 16m 33s (https://en.wikipedia.org/wiki/Equation_of_time https://en.wikipedia.org/wiki/Equation_of_time)

• CydeWeys 6y ago
  You need to multiply by 2 because it's drifting both before and afterwards, hence a little over 30 minutes of total drift.
  • _ph_ 6y ago
    For the question of the symmetry, only the difference to the noon point is relevant.