Most of the ETAs that we use come with 2 bumps on the detent spring/set bridge, each of which provide a 'stop' for each of the 2 stem positions. You need to grind off 1 of the bumps, which leaves only the 1 'stop' on the stem (for time-setting). I did this with my Phase 1 '42. Alternately, with some ETAs, you have the option of different detent springs, 1 having only 1 bump (for setting time) & the other having 2 bumps (for time & date settings). There are a few threads detailing this, but I cannot find them via the search. If I come across 1 of them, I will update this with a link.