There’s something I’ve always wondered about mechanical watches with a date. Does advancing the date start you of in the “AM” or does it stay in whichever half of the day AM/PM you were already in? I’ve been advancing the date by turning the hands to ensure I know which half of the day it’s set to, but maybe this isn’t necessary? Sorry if my question isn’t worded very well.
Changing the date does not affect am/pm.
Edit to add: if you do just change the date, check with your manual for what times it is safe to do this at - you can damage the mechanism if you change the date when the date wheel is engaged. On most mechanical watches the danger zone is within 21:00 to 03:00 but this varies so please do check.
This might not apply to all movements, but generally the hands indicate 12hr time in relationship to a 24hr basis that’s connected to the date indicator. Meaning, if you have the watch set to 6pm on one day, then quick-set the date to the next, it will indicate 6pm on that next day.