A year is not a whole number of days
The Earth returns to the same point in its orbit relative to the equinox in roughly three hundred and sixty five and a quarter days. A common calendar year is three hundred and sixty five, so each one ends a little before the orbit has finished, and the next 16 November arrives slightly early against the Sun's actual progress.
Early means the Sun has covered slightly less ground, so the solar degree on this date creeps down by about a quarter of a degree a year. Left alone for a few centuries that would drag the date backwards through the sign and eventually out of it. This is exactly what happened to the older calendar, which is why the reform of 1582 had to remove ten days at a stroke.
The correction, and the shape it leaves
Adding a day every fourth February pushes the date forward again by very nearly the amount the three preceding years took away. Over one four year cycle the accumulated slip and the correction cancel to within a few minutes, so the position on this date oscillates instead of drifting.
The shape of the oscillation is a small sawtooth. The year immediately following a leap year gives the highest figure in the cycle, and each of the next three gives a slightly lower one until the next leap day resets it. The whole excursion is under two degrees, which is why a single window covers the entire century.
The residual error, the few minutes the correction does not quite cancel, is handled by skipping the leap day in three century years out of four. That is why 1900 was a common year and 2000 was not, and it is the reason the window quoted here holds either side of both.
What the steadiness is good for
It means a date can honestly be quoted with a degree attached, which almost no birthday page does. It also means the sign is not in question: this position is several days of solar travel from the start of Scorpio and about six from its end, so nothing about a year or a birth hour brings a boundary into play.
Within a single day the Sun covers roughly one degree, so a birth just after midnight and one late in the evening differ by a fraction of a degree. That is enough to matter for a tight aspect and far too little to move the sign or the ten degree band.
There is a practical upshot for anyone who has been handed conflicting sun signs. On dates near a boundary the disagreement is real and needs a year, an hour and a city to resolve. On this one it is simply an error somewhere, and confirming that takes a moment.
The band, and the parts the calendar cannot fix
This position sits in the closing band of Scorpio, from twenty to thirty degrees, which the Chaldean order assigns to Venus. The tradition reads that band as the sign's persistence aimed at something particular rather than at everything alike, a convention carried down through the texts rather than anything measured.
The Moon is a different matter entirely. It moves about half a sign in a day, so on this date it can be in either of two signs depending on the hour, with no pattern across years to learn. The rising sign turns through all twelve within a day and depends on latitude as well as clock time. The widget above takes a year, an hour and a birthplace, returns the exact solar degree rather than the window, and reports the gap to the nearest sign boundary.
Questions people ask about this
Why does the solar degree hardly change between years?
Because the leap year rule exists to stop it changing. Three common years let the date slip backwards against the Sun by about three quarters of a day in total, and the extra February day returns it.
Is 16 November always Scorpio?
Yes. The position is roughly four fifths of the way through the sign and days of solar travel from either boundary, so no year or birth hour moves it.
What degree is the Sun on 16 November?
Between about twenty three and twenty four and a half degrees of Scorpio at noon across the last century. The widget above narrows that to a single figure for your own year.
Do century years change the answer?
Only slightly. Three century years in four skip the leap day to absorb the small residue the four year rule leaves behind. The quoted window holds across 1900 and 2000 alike.
Which decan does this date fall in?
The third decan of Scorpio, from twenty to thirty degrees, assigned to Venus in the Chaldean order and to the Moon under the triplicity scheme.
Does the birth hour affect anything here?
Not the sign or the band, since the Sun covers about a degree a day. It affects the Moon, the rising sign and the houses, none of which a date can supply.