Smooth background transition

Hi all,
I need help making a image transition into another image at night and in the morning.The watch face I’m trying to make is a transition from a day image to night (I have both images made). I would like it to be smooth and take about a minuet for it to do the full transition. So at night it would go from the sunny day image to the night image then back to the sunny image in the morning. I have tried messing around with it but this is my first face doing something like this, so all help is appreciated. Hope it makes sense, feel free to ask for more information and I’ll try my best to be helpful. Thanks for all you assistance.

Hi. For example, such formulas can be used to appear daytime and night-time images. They are time bound, but you can experiment with #WSh# #WSH# tags and so on.

Day
(sin((((#DH#+(#Dm#/60)+(#Ds#/3600)+18)/24)*360)*((pi)/180))*100)
Night
(sin((((#DH#+(#Dm#/60)+(#Ds#/3600)+6)/24)*360)*((pi)/180))*100)

cheers, I’ll give it a go.