As a new D2, I can give you a little insight into the schedules of both a 1st and 2nd year student. Note that what schedule you have depends on the individual student as well.
D1:
-Class from 9-5, 5 days per week, with early fridays in 2nd and 3rd quarter.
-Weekly projects in operative dent and fixed prosth
-Average of about 1-2 tests per week (didactic and pre-clinical) with a quiz or two as well.
Personally, as a student looking to specialize, I stayed after most weeknights till 8-9 to work on lab projects and came in saturday mornings as well. I mostly study for 5-6 hours for a day or 2 before most didactic tests unless I think it will be a bear (anatomy, endo). All students manage to have decent social lives during first year, and there's multiple city sports leagues, groups going out partying, big school events (Halloween party is a big one), a surf club, the list goes on.
All-in-all, it's a beast of a year, but it's very doable at a level where it won't completely dominate every waking hour. Except for 3rd quarter finals. They will rule your life for 2 weeks. 😉
D2:
Much, much easier year. Large gaps of time are allocated to self study, which can be used for boards study, studying for class, or surfing. Half the day is devoted to seeing patients in clinic, half to didactics (or self study). Didactics are on par with the difficulty level of first year, but lab classes seem to be easier, probably because we've become accustomed to it. You still have the occasional long day though, but weekends are usually completely open.
My day today:
6:00: Wake up
6:45: At school
7:30: Set up operatory for patient, get chart
8-10: Pedodontics and periodontics class
10-1: See patient for 28-30 PFM bridge prep
1-2: Eat lunch, deal with broken computer
2-4: General pathology seminar on blood diseases
4-5: Complete lots of paperwork
5-whenever: Do whatever I want. Tuesday night is a designated "do nothing" night for me. If it were tomorrow I'd study boards for ~ 2 hours.
Note that starting next quarter, we can see patients at night clinic sessions on monday and thursday nights (4 times/quarter). In third year you do it every thursday and monday night.
Let me know if there's any other questions I can answer. Additionally, remember that anywhere you got o dental school, it's going to be an insane schedule (Even at UCSF despite what some people here might try to tell you) 😉