but anything is possible depending on what you want to see. If you went to the floating markets they recommend that you get there really early, otherwise it is too crowded. As for the river kwai it depends on what you want to do there. If you only want to see the bridge then you would be able to do that later in the afternoon. The tiger temple is best to go in the afternoon when they lead the tigers out and you get photo's done. I think this is about 2- 3pm . Again it depends on what you want to see. If you just want a quick visit and photo's done you could probably do this in an hour or two then go on to the river kwai.
But realistically there is heaps to see and do. If you wanted to go to the cemetary, museum, erawan falls, hellfire pass and death railway to name a few you would need to stay there for at least a night and do a day tour that includes all these.
Hope this helps
Karin