write [buffer~] to set path, filename including current date & time, as .wav

After about 2 hours, I am at my wits end trying to figure out how to make this work.

I have a buffer~ with sample data in it. I want to be able to click one "write" button to send a message to write the buffer~ contents to a wave file with the filename "capture_" followed by the current date (yyyy/mm/dd), "_", and time (hh/mm/ss). The full filename should look something like this: capture_20160409_021430.wav

For this example, let's say the path is "OSX:/Users/MM/Music". I can always change it later in my patcher, but don't want the "write" button to prompt me for a path or filename, but to simply use the data I specify in the patch.

Goal: Each time I click the write button, it will write a new file with the current date and time in the same folder, which will allow me to continually write the buffer without ever overwriting any files.

Can anyone please help prevent me from pulling out any more of my hair over this?