Aug 31, 2010 - 7:34 AM
It's doable, but it's much. You will be full and tired of impressions after having visited the Jungfrau (I take it you mean Jungfraujoch?). After that racing to the Schilthorn, I don't know... I've visited both Jungfraujoch and Schilthorn, but I would never do it on one day.
I wish you a very pleasant stay in Switzerland, and it's April before you know it :-)!