Sun Square Saturn...

starts on December 25 (using a 1 degree orb), is exact on December 26 at 10.58am in Kilmore, leaves on December 27.  Sun at 4 degrees and 20 minutes of Capricorn, Saturn at 4 degrees and 20 minutes of Libra.

Squares usually represent tense periods of time, but also times when breakthroughs are made in the areas and relationships represented within your birthchart.  The Sun activates and highlights whatever it touches, in this case, Saturn: so the themes of responsiblity, contraction and hard work are being accented during this transit.

Quite often I see the fiery connection of the Sun, combined with the restrictive influence of Saturn as representing a pretty frustrating time... combined with the current retrograde Mars and with Mercury being stationary, I think that this is likely to be especially relevant.

So, by looking at where this aspect is in your birth chart you can get an idea of what or who may be involved in a frustrating situation, but that also has the potential to reach an important turning point.