On the faster day:
I am a plan/build/assess kind of guy.
I like to find a spot, lay it out first in frames, get a scope of how things works, and then upgrade once I have the rough layout completed.
Anything 60min or lower makes that process speed up much more quickly in a single player game. I typically will take over a POI vs. build my own from scratch, due to less time in the day.
On longer days:
The longer days equals more XP per day, ie faster leveling/game stage by day 7.
I like a slower pace between hordes, so I op for longer days as a solo player to give me time to prep. It makes horder night a lot harder, but I can properly plan an effective layout for a custom base at 90-120min days. 60min I am rushed the entire time.
The other aspect, if I am not mistaken, is food/water is based on real time game play vs in game time. Which means you will consume more in a 120min day vs a 60min day. I believe I read somewhere that actually player action affects thirst and hunger, which means you can run/build/fight a lot more in 120min than 60min. So that may be why as well. Even is statically attached to time + modified by ayer activity a 120min you will likely eat/drink more.