I've visited several "how sundials work" sites and can't seem to get a clear answer to this: is "sundial time" just a linear function of solar azimuth? More specifically:
When the sun is due south (northern hemisphere), it is sundial noon. All sites I've visited agree on this.
When the sun is due west (azimuth 270 degrees), I say the sundial time is 6pm, a quarter turn/day from noon. However, I can't find a site that actually says this, and some sites seem to disagree with this. Same for it being 6am sundial time when the sun is due east.
I know there are different types of sundials, but had always assumed they would give the same sundial time. Is that not true?
As a note, the sundial I describe above can be fairly inaccurate at times, which makes me question whether I'm correct.
EDIT (to clarify question): Forgetting entirely about clock time for a moment, suppose I build a sundial. When the sun is due west, my sundial reads 6pm. When the sun is due east, my sundial reads 6am. When the sun is due south, my sundial reads noon. My question: have I built my sundial correctly? The type of answer I'm hoping to get:
No. When you build a sundial, it should read (something else) when the sun is due west.
There are many different types of sundials. Depending on type, your sundial may or may not read 6pm when the sun is due west.
It depends on your latitude: sundials are latitude-specific. There's no such thing as a global sundial.
Yes, your understanding of a sundial is correct. Sundials can be off by as much as (some number/formula) from mean solar time, depending on your latitude. They can be as much as (some number/formula) from clock time, depending on your longitude and time zone.