Dot that move like seconds

hi, i have solved the problem with some photos that change every some hours.
i have follow the Tomaja instructions and now the watch work (not well, but ok).
at this point i have create only 2 dials (1 for 12 hours night and 1 for 12 hours of day).
but the formula of Tomaja don’t allow me to know how to fix a picture for 12 days.
can you make the formula for have the same picture for 12 hours ???
thank.