You can add days, hours and minutes and other values to the macro, the syntax is:
?(+|-)N(y|m|d|h|n)
+ to add value, - to subtract.
y - year, m - month, d - day, h - hour, n - minute
N - how much to add/subtract.
This is added to the end of your file name, e.g. ?+2d - add two days.
Example events:
C:\?yyyy-?mm-?dd.mp3 - it will use the today's date (as of time of writing, September 17, 2015)
C:\?yyyy-?mm-?dd.mp3?+1d - one day added, it will use tomorrow's date (September 18, 2015).