Traveling from Ljubljana to Zagreb in July. I am seeing conflicting/old information. Do I need to buy a train ticket in advance or the day of travel? All our other tickets were purchased in advance and I worry since it's peak travel season. But I can't seem to find a schedule, etc. Thank you.
It looks like there is only one morning train at 8:50am doing the trip in 2:45. The other trains take at least one hour longer, so you might want to buy your tix in advance when they’re available ( likely after June 14) at www.TheTrainline.com or from www.oebb.at/en Buses do the journey quicker (about 2-2.5 hours).
Definitely consider the bus (Flixbus, etc.). More departures/schedule options, perhaps
a bit cheaper.
In that part of Europe where the rail network is not well developed, buses are a much
more standard and viable option.
As mentioned above, trains in this region are scarce. Take Flixbus like everyone else does.