Option to specify a custom format for the {Date} placeholder in the file name?

Hi, I noticed that placing the {Date} placeholder in the pathFormat argument of the AddFile() extension method will make the lib put the current date in the format "yyyyMMdd" into the name.

Is there an option to specify a customized format. Other log files in my system use underlines between the poritions, i.e. "yyyy_MM_dd" and I'd like serilog to do the same.

Thanks