| 摘要 |
<p>The invention relates to electrical apparatus for indicating one or more prescribed times of day which occur between the hours of sunset and sunrise. The apparatus is photosensitive and operates in a manner so that the selected prescribed times are determined each day by utilizing detected sunrise and sunset times as the basis for the determination. This determination on a daily basis avoids accumulation errors which occur when the determination is on a cyclical basis as with the use of a clock.</p> |
