Correct .
EDIT:
And further. March is an important month in the Balkans, also another reason I flagged this month as the Axis invasion, instead of the earlier Italian invasion of Greece of October 40.
(...)
I see this one single decision as the most important reason Germany lost the war. Hence why I mark this date.
Thanks for your answer, Dale.
My main concern was about Python and playability, more than History.
I guess the line you need to edit is the turn number (around the end of the file), not the date (around the middle).
I'll report my Immortal game with UE in my thread, to avoid to spam this one. Here, just some variations i made to the XMLs:
Civics:
In the UE Police State gives +50% science, opposed to Retail where it gives -25%. IMHO this is a contradiction, but...

To partially balance this, i added +3 beakers/specialist to Democracy (like Representation in the normal game)
Buildings
I gave the Goods Factory +50% from power, otherwise what is the use for Coal Plant? boil the water?
Also, restored +25% for any factory (Goods and the 4 military) like in Retail, but no bonus from power.
Units
Artillery
Gave to Heavy and Modern the "no damage from collateral" like in Vanilla. Retained the early Artillery flat.
Anti-Tank Guns/tank destroyers
Totally overpowered both. The A-T Gun with its +400% means a strenght of 25, with the defensive bonuses it's almost unbeatable even for Modern Tanks.
The T-destoyer with 15+100% means 30, with the defensive bonuses it's impossible for everything, even in the field.
Lowered A-T gun to +200% (hard, but doable for the early tanks)
Lowered the T-destroyer to 10 strenght, yet hard for tanks, but easy for infantry
Made some balance for units: some, mainly planes are IMHO clear typos.
It's too long to describe, if you're interested i can post the XML.
Map
Global assault is plenty of resources, Europe and Pacific almost completely empty.
I gave some in the very first turn to everyone (at least, to everyone will have to fight). To be honest some more to my faction
Science/Production
Noticed you doubled the science cost: a bit much, IMHO. I took an half-way.
317 = 7.000 UE = 14.000 I changed in 10.500 (is for friends and enemies, but otherwise research will not count much) ---- with "substitute all", not one by one

)
Also, i gave to all the colonial cities (mines and enemies) goods factories, otherwise the colonial powers are disadvantaged: you pay the maintenance for cities that in the best case will produce science, and not much, since they take forever to build, a laboratory, or even a naval dock or an infantry.
Stack attack
Learned how to use, like the AI does. 2 Examples:
- Germany has more than 150 assorted tanks, some 60 improved infantry, 10 artilleries, and some assorted units: i managed to wipe them with some 30 Heavy artilleries and some 20 Crusaders. The important is to let them unpromoted in the first assault
- the most challenging was Italy with 38 artilleries, 40 tank destroyers, 60 assorted infantry in a single stack: over 30 heavy artilleries wasn't enough, luck they stay on Venice: brought the 90% of the impressive British Fleet with 10 marines and attacking alernately from sea and from land i managed to wipe them in one turn... game over
The counterside of this is that you gain very few GGs: the units simply evaporate with no actual fight, so in the end of my game i has only 3 GGs.
What i cannot understand is why they keep those large stacks and let the cities with no more than 5 units.
Also Germany kept the above described stack in the field in his territory, sheltering in the closest city after my first assault (thanks, so i can promote my units to CR) instead to go after France 7 or more turns before.
Same for Italy: why they moved from Turin to Venice instead to roll France starting from Nice? With a stack like that the enemy units evaporate, no chance.
Canada was great: managed to take some German cities in a human-like way of play.
Of course, no criticism on the above, maybe a contribution (i hope) for a very great mod.
What else? thanks a lot, again and again.
ciao