Editing Gnomon (section)

==Orientation==
[[File:Gnomon normalized.jpg|thumb|right|Gnomon situated on the wall of a building facing Tiradentes Square, [[Curitiba]], Brazil]]
{{further|Polar alignment}}

In the [[Northern Hemisphere]], the shadow-casting edge of a sundial gnomon is normally oriented so that it points due [[true north|northward]] and is [[Parallel (geometry)|parallel]] to the rotational axis of [[Earth]]. That is, it is [[polar alignment|inclined]] to the northern horizon at an [[angle]] that equals the [[latitude]] of the sundial's location. At present, such a gnomon should thus point almost precisely at [[Polaris]], as this is within 1° of the north [[celestial pole]].

On some sundials, the gnomon is vertical. These were usually used in former times for observing the [[altitude]] of the [[Sun]], especially when on the [[meridian (geography)|meridian]].

=== Style ===
The ''style'' is the part of the gnomon that casts the shadow. This can change as the Sun moves. For example, the upper west edge of the gnomon might be the style in the morning and the upper east edge might be the style in the afternoon.