renamed to cellSize.

I tried this https://patchthecode.github.io/CommonQuestions/#1 and change itemSize to cellSize

and this is cellSize = 20

this is cellSize = 40

this is cellSize = 50

the grayed dates (which is red now since I changed the color) is still there

Im not sure what you want to do.
CellSize changes the cell size.
But if you want to "remove" the gray colored dates, then simply set their visibility to hidden.

if cellState.dateBelongsTo == .thisMonth {
   myCell.isHidden = false
} else {
   myCell.isHidden = true
}

thats it. Put this in your cellForItemAt function.

ow thanks. cheers