So they depend on the user referring to something called the Equation of Time to convert sundial time to actual time.

Not necessarily, or at least without explicit calculation. Good sundials are marked with a calendar that does that for you. Large analemmatic dials have places marked for each month where you stand the gnomon, which can be a person. There is one by the river in Stratford Upon Avon

https://www.geograph.org.uk/photo/6232719

There are also dials that include a kind of circular slide rule that implements the equation of time:

http://www.short-humour.org.uk/Heliochronometer/Heliochronom...