Dual-casted lasts a long time.
I suggested a "Luna Moth" Master Alteration spell, which would summon a brilliant luna moth to stay by your side until you interact with it and tell it to go away.
That sounds like a gret spell

Its such a pain to keep summoning my tiny ball of light that doesnt illuminate very much every minute.
Youd think that there would be higher versions of spells, but no.
This is why we need spellmaking and why its removal is nothing but bad.