Help please - GMT resets date at noon

[Ursa Major]

My Z serial 16710 is giving me an issue, and I'm not sure how to resolve it. My understanding is that there is no quick-date function, that has to be changed manually by using the 24 hour hand. Here's the issue - the date changes when my 24 hour hand passes 12 noon (i.e. the bottom of the dial at the 6 o'clock position). For instance, right now both my hour/minute hand and my 24 hour hand indicate that it's just past 7:30 am MST, and both will keep good time all day, but the date will flip from "6" to "7" at noon. How can I get the date function synchronized with 24 on the 24 hour hand, rather than 12?