Rotate is quite ok for drawing the hand.
What I wanted to say is that you might need 60 images each containing the background for each minute.
I still feel it might be doable to restore background images based on the clock hand, if you have reasonably fast flash access and know where the picture data is (it does help if the data is stored continuously, so not having it scattered over the flash in different sectors; haven't studied the file system to see how the FS works).
How much time do you think is needed to read a byte from flash at a given position?
How much time to write a byte to LCD?
And of course this does require low level access to make it performant.
I'll see if I can come up with some pseudocode or C code to illustrate what I want, but it may be Friday or Saturday before I get to that.
I'm not sure I understand... The code I'd posted above draws two clock hands over a solid background image.
drawImagescan handle transparency and rotation so it's pretty easy to just rotate a hand wherever you want it