When you go to sleep anywhere you seem to get up at 6 in the morning. If you go to sleep at 5AM not much time passes but if you sleep later in the morning you'll be out for almost an entire day (seemingly, I've not done extensive experiments). Is this a problem?
Are there any mechanics in the game that are based on the amount of time that has passed?
For the purposes of this question I'm not counting things that require a certain time of day such as the hunts where your target only comes out at night. They require certain times of day but the amount of time passed isn't relevant.
Best Answer
No, there are no penalties for sleeping more, aside from not being able to gain a massive amount of EXP all at once, as mentioned in my answer here.
However, a potential benefit to sleeping excessively is that if you choose to camp outside, Ignis' dishes can give you various buffs for the following day, which can be greatly beneficial. (My favorite buffs are ones that put Prompto's HP on par with the rest of the party)