Formal or literary term for sunrise, often used in contrast with 日没 (sunset). In everyday speech, 日の出 (ひので) is more common.
See also: 日没
I check the times of sunrise and sunset.
日出 is the formal, technical term for sunrise that pairs with 日没 (sunset) in weather and almanac contexts.
Compound of 日 (sun) and 出 (to come out), following classical Chinese word formation. The reading にっしゅつ is the on'yomi (Sino-Japanese) reading.