Daylight Detector

Channel the heat of the sun through the chunk of fluorite. The fluorite will not be destroyed in the process. It will glow brighter and brighter until it becomes uncomfortable to look at by the end of the 1 minute casting time. After this point, the light will dim, and the caster will know where the sun is relative to them. To the caster, they will have to close their eyes, and in the darkness around them, they will see a spot of light representing where the sun is.

For example, if the sun is below them, then they know it is about midnight, if the sun is in front of them (and they're facing the right direction) they will know that it is sunrise.