Since our calendars are approximately 1/4 of a day off can it be accurate astrologically to say some

[Astrovalley]

Since our calendars are approximately 1/4 of a day off can it be accurate astrologically to say someone born at 2:00 PM Jan. 19th would be a Capricorn? How does leap year figure in?  

As far as I know the heavens (stars, constellations, planets) have no awareness of earth's calendars. The planets' movements have been observed, studied, measured and mapped for many centuries. And it was found that the heavenly bodies move on a precise path and at constant and predictable speeds. Astronomers and astrologers have long prepared tables and published them in booklets called an ephemris (single year) and ephemerides (collection of several years). Astrologers in the past and some very few in the present use these to calculate horoscopes. However since the astronomical data can be programmed into computers with cutting-edge accuracy, most astrologers prefer using computer-calculated instead of hand-calculated horoscopes. Astrology calculation programs can, in a split second, calculate an accurate horoscope (the chart 'wheel') which would require several minutes or much longer to prepare by hand -- which requires some math and, of course, the potential for human error.