Measuring declination in negative hours of arc?
It's not hours, minutes, and seconds, its degrees, arcminutes and arcseconds.

There are 360 degrees in a circle, 60 arcminutes in a degree and 60 arcseconds in an arcminute.

Since the planets lie close to the ecliptic, and the ecliptic tilted at 23 degrees relative to the equator, the declension of the planets rarely exceeds +-23 degrees, giving an appearance that their dec. is like a time.