leap years and Moshe's birthday

The Midrash has a machlokes when baby Moshe was placed in a basket and put in the Nile: on 6 Sivan or on 21 Nisan (see this post where we discussed what the machlokes is all about).  According to tradition, Yocheved was able to hide Moshe for three months before having to send him off because the Egyptians counted on babies being born full term, but Moshe was born three months early.  According to the view that Moshe was put in the river in Sivan, counting three months from 7 Adar is a no-brainer.  But how do you get three months from 7 Adar to 21 Nisan?  The Midrash answers that the year Moshe Rabeinu was born was a leap year, and we count partial months as full months: Adar 1 = month #1, Adar #2 = month #2, Nisan = month #3.

It makes more sense to assume that the two views in the Midrash are not in disagreement about the calendar.  Since there was no mitzvah of kiddush hachodesh yet, the determination of how many months in the year must have been according to some cheshbon, or maybe according to G-d, but it’s not the sort of thing that easily lends itself to disagreement about in sevara.  It’s fair to assume everyone agrees that the year Moshe was born was a leap year – the question is whether he was born in Adar 1 (so the three month count ends at Nisan) or in Adar 2 (and it ended in Sivan).

Is there any way to figure out whether the year Moshe died was a leap year or not?  I have no idea, but maybe someone else does.