In Psalms 81:3, it says:  "Blow up the trumpet in the new moon, in the time appointed, on our solemn feast day."
Dr. Strong clearly defines the phrase in the time appointed as the FULL MOON in his reference number 3677, which comes from number 3680.  Therefore this verse could then read: "Blow up the trumpet in the new moon, the time of the full moon, on our solemn feast day".

This would seem to say that the full moon is the New Moon, and NOT the first light of the moon.  Is this saying that the New Moon is the "full moon"?  It certainly can be read to say so, as it would appear that this solemn feast day, the New Moon, is being referred to as the time of the full moon.

What is your thought on this scripture which apparently says the New Moon is the full moon?

I have been asked this question many times and have reviewed my position on it many times.  Strong's work has errors in it; it is not to be expected that any work is perfect.  In addition, I have learned not to trust just one reference on an item.  Most Hebrew words have multiple meanings; some errors come from the fact that prior to 600 C.E. there were no standardized vowel points.  Other problems of translation come from the significant differences between Biblical Hebrew and secular Hebrew, which have changed over the centuries as all common use languages do.

I have personally studied the Hebrew (Biblia Hebraica Stuttgartensia), and I would translate Psalms 81:3 this way:
"Blow the trumpet at the new moon, in the fullness of our festival day."
As you probably know, you will find versions that say full moon and versions that do not; so the best of Bible translators do not agree on this one.
And so, it is up to us to "walk it out" as the Hebrews say; that is, for each individual, or group, to decide how they will do it.

After watching many, many moon cycles on a daily basis year after year, I feel that the disappearance of the moon for one or two days just before sunrise creates a natural kind of a break.  In the moon cycle, there is about one week of the moon progressively getting higher in the western sky just after sunset, and then about one week of the moon getting lower to the east after sunset; and all while growing in size.  Then, when the moon is not visible in the east right after sunset,  it is the next morning. One can now continue to follow its movement in the morning; it will be low in the western sky just before sunrise.  Now the moon will cross the sky, west to east again, but in the daylight hours; and it will be getting progressively smaller.  Watching this daily trek eastward across the sky each morning before sunrise for about two weeks, one will finally not be able to see the moon before sunrise nor right after that day's sunset either; this will last one or two days.  This is the "natural break" I referred to above.  Astronomically, the conjunction occurs during this time when you cannot see the moon.  After this one or two days, the crescent moon will be visible in the western sky just after sunset.  Now this cycle, observed by men for centuries, begins again; hence this "reappearance" of the moon as the crescent after one or two days of not being able to see it, is called the "new moon."

P.S. The Hebrew word for "appointed time" is moed.  The word "moed" does not appear in the Hebrew text of Psalms 81:3; the KJV translators took some license with this.

In my opinion, the Scriptures do not state that the full moon is the new moon.
Observation would seem to support that after the "natural break" in the visible moon cycle, the reappearance as a thin crescent should be called the "new moon."