It may aswell have been two years i'd even say 10 years.
How can you say that? It is not even 2 years.
Time Frame Guideline perspective v1
White Zetsus attack on all fronts.
Darui's sea-side attack? Neutralized and the sun have not even set yet. Next Wave? Still..the sun have not set yet.(All other battles have a similar time frame)
White Zetsus disguise as shinobi attack came around. Naruto answered the call quickly and rather promptly when the threat came out. Result: Neutralised in a few days tops.
Naruto hits the battlefield after a brief while of speed kyubbi mode travelling.
5 Kages summoned. Battle ended in less than a day.
Edo-Madara is summoned. Meteor summoned. Many deaths. The sun was burning brightly .5 kages head out there and the real naruto goes after obito. It was evening at that.
It was around night when Madara jumped down from the sky to obito's location. The moon was high in the sky. They battle. Shinobi alliance arrives. They battle. The moon is still in the sky. Around around like 20 chapters of battling , obito told naruto that the next day was his parents deathday. ( This indicates the day have not even passed yet , and the moon was still in the sky). Battle between alliance and madara was only happening within the span of the night
Add that time frame up together? Less than a month