1

Scenic, yes, very much, especially the part along the Baikal Lake. And forest scenery leading slowly to hilly steppe-like, open land.
Not sure there are many day trains, though...Could be done by bus too.

2

Well, the train ride itself was quite scenic. However, most of the trains run at night and you won´t see anything.

If you hike around Lake Baikal and get a picture of what it´s like, I don´t think you´ll really miss something with a night train. I did some walking around Port Baikal along old Circumbaikal railway tracks, got amazing views of the lake. And took a night train to Ulan-Ude from Irkutsk. Of course, if you have plenty of time to spend, you may easily opt for a day train. In my case, I was quite on a tight schedule, as usually.

I checked the Russian Railways web-site and it seems there just some trains leaving Irkutsk around 4-5 am, most of the trains leave in the evening or at night (however, the schedule may change in summer). To search for trains, check here: http://eng.rzd.ru/schedulee/public/rzdeng?STRUCTURE_ID=46

When are you planning to go?

3

I'm going to be there at the end of December, i've currently got plans to spend 3 days at Olkhon island with 2 days planned for travelling there and back, 1 day in Ulan Ude and 2 days in Ulan Bator, i'm trying to decide if i should take a day off ulan bator and either take the day train or add a day for Irkutsk or another day to one of the other places.

4

I´d suggest you to add an additional day to Irkutsk or Baikal. Irkutsk is a lovely town with nice old wooden architecture. Really liked the place. Baikal is... Baikal:) If traveling to Olkhon, it may make sense to stay there longer (I´d do that if I went there). I think with this tight itinerary a day on a train will be a real waste of time.

Not much to see in Ulaanbaatar. However, Mongolia outside UB is gorgeous. One day for Ulan Ude is enough - it´s an interesting place, with an old Soviet-time atmosphere. Seemed like traveling in time in some places. Good experience, but not worth more than one day without any particular reason.

5

Look for some threads about Mongolia is seven days and what to do with a short amount of time there. It is possible to get outside the city with only a day or two but you need to do some research prior to arrival otherwise all you will see if the city.

Half a day in Ulan Ude is probably more than enough.

Ruth

6

I've already got a 5 day dog sledding trip in terij national park worked out, i just had another 2 days planned for Ulan Bator on top of that.