H E = 15 ∘ × t  (hours) . {\displaystyle H_{E}=15^{\circ }\times t{\text{ (hours)}}.} The uniformity of their spacing makes this type of sundial easy to construct.
H E = 15 ∘ × t ( h o u r s ) {\displaystyle H_{E}=15^{\circ }\times t(hours)} 均勻的時間間距使得這種類型的日晷很容易構建。