Placed in front of the Roukokumon is a sundial called Nichiei-dai. Upon restoration of Shurijo the sundial
was placed in the exact same place as it was in the old times. It was used as a supplemental tool of the water clock.
It is said that in 1739, since the former water clock was considered imperfect, the first Nichieiki was manufactured
and set in its place. Since then, this time system was in use until the abolition of feudal domains and the establishment of
prefectures in 1879. In the Kingdom of the Ryukyus, the sun dial marked high noon as well as the hours before and after noon.
A water clock was used to keep more precise time.