Just a layman:
The system leans towards moving cases forward and the defendant has right to have it move forward and I'm not sure the deployment of your spouse is a sound reason why you cannot be present , especially second time around, its sort of up to judge to grant or deny. Depends....
To some extent all your personal schedule needs are subordinate to the courts need to move it, you requested it now you make yourself available.
(Don't let enemy know you have schedule difficulties--they will attempt to force a schedule unworkable for you.
Whenever I've needed to get a postponement I've good to Judges office and by asking nicely I could generally get to pick a time and date in some range. The clerk who schedules the Judge probably has a lot of weight as to if its a yes or no--and asking in person may hold weight and if you get a yes you file to form right then.
Of course if you use counsel they seem to have 101 ways to get delays
My suggestion, if your witness is available, make time!