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Hi, I'm Mike G and I'll be glad to assist you. Please be more descriptive on the switch wires, type of switch, number of wires and their colors. Your previous description is confusing regarding the red wire.
OK, the single black wire on the gold screw connects to the red timer wire.
The blacks on the other end if the old switch connect to the black timer wire.
The white timer wire connects to the whites in the box
The green connects to the bare copper wires.