Ok. I'll explain more thorow how I see it. First of all did you play Dragon Age 2? If you did you may remember how time worked there: it had plenty of timeskips (and that's not very good for an RPG and immersion), but also a frozen world (which we already have in BG3 and we know that there are some players which love its convinience) and quite a lot of quest that were set at different time of a day (something some people want to see in BG3).
So I'm suggesting a hybrid of that with what we already have. Literal actions like walking, managing inventory, looting and smacking someone with your sword shouldn't change the time. Completing quests, considerable main story progress and long rests should change the time, but their time cost should be a bit bloated to compensate those time-free actions.
And if Larian would set certain quest for certain time of a day they can do what Bioware did in DA2: add special time-skip option that activates by player. In DA2 it literally worked like "now you have a quest for the evening while it's morning, either do something else or go to your mansion and time-skip".
So no one would be really soft-locked from anything. If you need to loot some resources you can loot for eternity, if you need to walk back to your camp you can do it, but you cannot pack all quests in one day.
I think I understand. And yeah, I like this! I want there to be day- and night-time in BG3, with appropriate quests and potentially even different NPC availability for each. This would massively increase immersion and also allow for Larian to add night-specific creatures like vampires to excel at night but suffer during the day. (@GM4Him has suggested that short rests are these mini-fast forwards of ~2-6 hours).
But. This seems more appropriate for the "Day/Night Cycle" megathread, as it doesn't directly relate to long rest/camping restrictions (since you say that players can "time-skip" = no restrictions besides possibly timed-quests?). Or at least you're coming at it from the opposite end. Your suggestion prevents too many
events from happening in the same game-day, whereas I want to prevent too few
events in the same day. So I think a combination of your Day&Nighttime system and some other rest restriction system would be good. The former adds a reasonable sense of time progression and day-/night-specific quest opportunities, and the latter limits the player's ability to pass infinite time and bypass 5e's balance around long-rest-recharge abilities (namely spells). And either can be implemented separately.
DA2 worked very well with this system because abilities were cooldown based. Whereas in 5e, the different classes are balanced around assuming 3-6 encounters per day. If Larian wants to retain this balance (some players don't think this balance is important), BG3 requires either rest restrictions OR changing the classes' abilities to something closer to per-combat uses.