Then Heidi went on to give him an account of the whole day and how delightful it had all been, and particularly described the fire that had burst out everywhere in the evening.  (Heidi told him of the mountain with the great snowfield, and how it had been on fire and had turned rosy-red and then all of a sudden had grown quite pale again and all the color had disappeared.)  And then nothing would do but her grandfather must tell how it came, for Peter knew nothing about it. Then Grandfather explained to her that it was the sun that did it. "When he says goodnight to the mountains he throws his most beautiful colors over them, so that they may not forget him before he comes again the next day."  

– Heidi, Johanna Spyri

When we read about about Heidi's delight seeing her first mountain sunset I knew just how she felt. For just a few moments morning and evening the sun and the mountains meet, either those just behind us or the ones on the island to the west.  Some nights it is almost unbearably beautiful. 

Light chasers might want to check out the app, Skyfire, which is said to be about 80% correct when predicting when and where the sky will be most brilliant.  I have only just downloaded so I can't comment yet.