The utility model discloses a sun altitude vertical line sundial with
time difference correction, which comprises a
latitude plate and a date and time plate,
latitude scales are arranged on the front surface of the
latitude plate, the date and time plate is rotatably arranged on the front surface of the latitude plate, a date and
time table is arranged on the date and time plate, and a pointer is connected to the vertex of the date and time plate. The right side of the latitude plate is rotatably provided with a
telescope cylinder, the
telescope cylinder is connected with a sun
telescope, the telescope cylinder is connected with a counter weight line, the back side of the latitude plate is rotatably provided with a true usual difference ruler, the back side of the latitude plate is provided with date scales,
longitude scales, a true usual difference curve and
longitude time difference scales, and the true usual difference can be read when the true usual difference ruler points to the date scales. The true
longitude scale and the longitude
time difference scale can be read at the same time. The device can be widely applied to different places, can measure the solar
elevation angle in real time, determines the current moment according to the solar
elevation angle, can inquire
sunrise and
sunset moments every day, and can perform double correction of longitude time difference and true flat sun time difference.