The year has 16 months.. you learn something new every day.

Guess I jumped the gun and mistook September for October.
(And I meant Calendar Year, not Fiscal Year.)

Had you said trimester instead of quarter you'd actually been correct

Week 36 Breakdown:

PlayStation 4: Up in the United States; Down in Europe, Japan, and the Rest of the World; Down overall.

PlayStation 5: Up in all regions

Xbox One: Down in all regions.

Xbox Series: Up in the United States, Europe, and the Rest of the World; Down in Japan; Up overall.

Nintendo Switch: Down in all regions.

----------------------------------

No. When talking about years trimester and quarter is the same thing. Trimester means a three month period and since a year has twelve months a quarter is also three months.

Might be a language difference, as here a trimester is generally understood as a 4-month period, with 3 trimester forming a year. (2 semester, 3 trimester, 4 Quartals...)

Week 37 Breakdown:

PlayStation 4: Down in all regions.

PlayStation 5: Down in all regions

Xbox One: Down in all regions.

Xbox Series: Up in Europe and Japan; Down in the United States and the Rest of the World; Down overall.

Nintendo Switch: Down in all regions.

-----------------------------------------------

This was an interesting week. Back in 2014, Destiny came this week and it catapulted the PS4 to over triple its baseline and nearly doubled the Xbox One's baseline. As such, the PS5 and Xbox Series are taking rare Ls this week.

Week 38 Breakdown:

PlayStation 4: Up in the United States; Down in Europe, Japan, and the Rest of the World; Down overall.

PlayStation 5: Up in Japan; Down in the United States, Europe, and the Rest of the World; Down overall.

Xbox One: Down in all regions.

Xbox Series: Up in all regions.

Nintendo Switch: Down in all regions.

Week 39 Breakdown:

PlayStation 4: Up in the United States; Down in Europe, Japan, and the Rest of the World; Down overall.

PlayStation 5: Up in the United States and Japan; Down in Europe and the Rest of the World; Down overall.

Xbox One: Down in all regions.

Xbox Series: Up in the United States and Japan; Down in Europe and the Rest of the World; Down overall.

Nintendo Switch: Down in all regions.

-----------------------------------------------------------

So this week marks the last week of September for this year and we find the PS5 and Xbox Series down this week. This is due to the launch of FIFA 15 for the PS4 and Xbox One in 2014, as you could tell from the boosts for this systems in Europe and the Rest of the World, the two strongest regions for FIFA by far. Soccer, man, it's like a freaking religion over there. As a hardcore baseball fan, fairly avid basketball fan, and casual football fan, I laugh whenever I see someone from America talk about how either one of those 3 sports are the biggest sport(s) in the world. 

This week also marks the last week before the Switch OLED model releases and that should lead to the Switch getting a sizeable boost next week. Just in time for the REAL last quarter of the year.

JFYI I believe this week and week 37 were the ones when Xbox One launched in many European territories back in 2014, so it's not only Destiny and FIFA which helped Xbox One to win against Xbox Series these two weeks.