G10 offsets not working as expected

I’d like to use G10 to adjust my work offsets, but I want it to be relative. For example, I’d like to change my Z offset by one inch. I tried this code
G91 G10 L2 P2 Z1.0

But this just set my Z offset to 1.0. It didn’t add 1.0 to the existing offset. Is there another way to do this?

Scott,

You can use G92 to shift the work coordinate.

Thank you,
Norman