I skied Daltind in April myself, and it is really great. However, I've read elsewhere that it is often ok to ski in June, even as late as early August. See e.g. http://www.home.no/tolarsen/daltinde.html
True, Daltind is known as the last great ski run of the seasons for many of the locals. I'll clarify the ski season on the main page, as the mountain itself is skiable almost year round, though the approach is not. If you have any pics to add to Njallavarri, please do so, the page really needs some more. Takk, og vi ses i fjella, og god påske!