Trailing 12-Month Visual

I'm not sure if there's a way to dynamically alter the start/end points of a visual like that, but you could use some logic to get the same result with a filter - if you use the correct combination of dateadd/eomonth/today, you should be able to define each record as being in the previous twelve months or not, then use it as a visual level filter

edit - I've completely forgotten that there's relative date filtering as an out of the box option, try dropping your date field into that as a visual level filter and seeing if previous 12 calendar months will get you what you want?