Great questions!
This will vary a bit between the 4 year and 5/6year programs and between schools. In general the first two years of the 4 year program are a compressed version of the first 3 medical years of the longer programs. The people in the longer programs have more free time and may be better able to hold down a job or research or more ECs. The last two years are largely the same for all programs.
I went to a four year program at RCSI and graduated n 2011 my days were generally as follows:
Year 1: Classes 8-2 during weekdays with 1-3 days going till 5(anatomy lab and clinical skills). Half days of early clinical exposure were added to that schedule starting after Christmas. Classroom schedule was posted well in advance and attendance was documented at some lectures and all clinical teaching sessions. Most of the material was advanced biology and relatively easy for me as I had a BSc in bio. The humanities majors worked a lot harder. There was also ClinEpi and Ethics, There was a one month full time clinical placement in June. I studied for 2-4 hours per week with some cramming the 2-3 weeks before exams after Christmas and in May.
Exams were a mix of MCQ papers and short answer papers and were usually quite challenging with a mean of about 60%. 50% was a pass. A score of over 75% was prize worthy. There were also oral exams and observed clinical OSCEs (clinical scenarios involving patient interaction). There were no hard fails on exams in Ireland. If you failed the first sitting you wrote a repeat exam (different questions, same material) usually before the start of the next academic year. If you failed the repeat you failed the year and had to repeat the whole year including the material you passed. I found the evaluations very fair but the grading system took some getting used to. Coming from North America, the routine inclusion of material beyond the syllabus on tests to determine prize worthy performance was the biggest adjustment. The standard paper included questions specifically put there with the expectation that no student at the level taking the exam would know the answer. I had to adapt to having WTF moments on every test. Repeat exams are common (1-2% of each exam in the 4 year program, up to 10% in the 5/6 year). Repeat years are uncommon (1 person in my class over all 4 years). Failures are very rare(haven't heard of anyone).
Intensive socializing is the norm at least on weekends for first year as you bond with your classmates. There are University sponsored events, club nights, medical nights, Canadian nights, formal balls...it goes on and on and continues for all the years of med school. Participation is high. Most people say that their Med school time in Dublin was some of the best years of their life. I'm not an out-going social guy but I always had a place to go Friday nights.
Most people take 2-10 trips/year to Europe (easily doable on long weekends or holidays). You hear a lot of 'I am going to take advantage while I can' talk. In retrospect, I could have taken a job during first year but most don't. Research positions are taken by some, some paid, some voluntary (that part is the same no matter where you are in the world).
Summer off -some people do research or Observerships; some take a long vacation. I don't think it matters in the long term.
Year 2: Similar schedule to year 1. Two more months of clinical placements in January and June. No more anatomy but path lab and more clinical afternoons take the time. The material is more novel and requires more independent study time at this point I was at 3-5hours/week. Socializing decreases slightly. People still take lots of trips. I think it would be difficult to hold down a job from this point onwards. I did a lot of volunteering because I like it and to boost my resume. I suppose you could trade that off.
The summer is off. I did Observerships to figure out what electives I wanted to get the next year and to make some contacts back in Canada. Most people take the USMLE 1 at this point. The USMLE score (and all the test scores Step 1/2, and EE) matters and will likely require extra studytime. Practically you can only write these exams once and you have to get a high score. As a rough guide, think about how much time you put into the MCAT (or SAT if you're a high schooler) and double it. More than double it if you score low on these things.
Year 3: Full time clinical placements start as you rotate through the core medical specialties (Paeds, Obs/Gyn, FM, IM and Surg) A substantial part of this time is spent in community hospitals outside of Dublin. The University arranges housing. There is also 5-10 hours of classroom time per week. There are no mandated call obligations which makes things a bit easier compared to North American med students. The schedule is generally 7 or 9 - 5 weekdays with weekends off. Late nights watching some surgical procedure or voluntarily helping out with call are uncommon but most keen students will do about 1 a month. There are also some shifted rotations like labour and delivery and Emerge/A&E that may disrupt the normal schedule or require weekend work. Independent study requirements greatly increase. I did 10 hours per week with cramming starting at least one month before exams in May (no Christmas exams this year)
The real challenges start cropping up here in arranging electives and navigating the huge amount of paperwork required to stay on track to match at the end of year 4. You need to pick a specialty to target for the match and a geographic target. You need to learn everything you can about matching to your target and possibly modify your ECs and electives to meet their requirements. Consider contacting residency Program Directors to get the inside scoop. Finally and probably most importantly, you need to draw up a comprehensive schedule so you don't miss any deadlines as there's no room to recover from an oversight. It is a huge help to have other students around going through the same process or ahead of you that you can draw on.
I'll highlight a point here: if all that socializing has paid off and you've formed part of a bi-national couple it may complicate your long-term planning. It's very funny that so much of this forum is devoted to concerns about matching. The major life plan change to allow for the destruction or accommodation of personal relationships was a much more common (in my class at least) issue than failure to match. If you're planning something like immigration that's a whole lot more paper to keep on top of. I don't know if there's any good advice to give here but it's something to ponder when you're thinking about everyday life at school abroad. I digress....
It would be almost impossible to keep a job at this point (though people manage ECs and volunteering). Most people still take trips at the same frequency as year 1 and 2.
Summer: This is the start of the year of hell. Summer is occupied with as many electives as you can get and you have to blow them out of the water to make your contacts and get fantastic LORs. You'll also need to meet with program directors to learn how to structure your application and to express interest in particular programs. If you're applying American you do both parts of the Step 2 between June and November and you have your applications in by September. If you're going Canadian you write the MCCEE and USMLE 2 and do the American applications as your back-up (or develop some other back-up plan).
Year 4: Clinical rotations continue as in year 3. There's some short added courses on ethical practice, practice management, conflict resolution and a few others. The students shooting for Irish intern postings start working very hard to get a good class rank and generally don't worry about anything else. Socializing decreases but never stops (it's Ireland after all) American residency applications start rolling and interview invites start appearing. People applying to the American match need to travel to the states for interviews at random times throughout the fall. Usually no formal allowance is given for this from the Irish Schools but they turn a blind eye provided no Staff complains and you don't take ten or more prolonged trips. Canadian applications are due at the end of November so some people will be busy writing those. Some people try to squeeze in an extra elective over the two or three week Christmas break. Again no Christmas exams. Most people do not have time to travel.
After Christmas the Canadian interview season starts and runs over a four week block. RCSI had a formal arrangement to give Canadian students a break to cover the interview period. Clinical work continues in the core medical program and everyone starts prepping hard for final exams. Match day comes up in March and North American students find out their fates. Some will check out after matching and do barely enough work to get through exams. A few unlucky people have to enter the US scramble matching process or the Canadian second round match.
Final exams come around in May and most people freak out to a greater or lesser extent. Some people will retreat home or to the library in a panic and you won't see them until they get their medals at graduation.
Exams finish, there's usually a big class trip to somewhere tropical. Some of the Canadians will write the MCC QE1 after the Irish exams (though this exam can be delayed until later with no consequence to residency). Results are published, some people--usually expected--don't pass and have to repeat. After all the Irish results from all schools are published the students staying in Ireland find out where they will be Interning.
Graduation is a big event. Lots of teary and sometimes destructive goodbyes and people trickle off to the next stage in their lives.