The parameter name would be “Date” and it can be added both for files and directories. The parameter contains the modify date of an item in Unix time format. I’d leave it up to the sending client to decide for which items this information is added. AirDC++ 2.50 adds this parameter for all items in partial lists, but only for directories in full lists.
Comments about this topic:
Letting the requester to decide doesn’t seem like a good idea since it would increase the number of different file lists that should be generated. Generating a single file list may take several minutes and users may have different share profiles available that already require different file lists to be generated. If the requester is afraid of the size of the file list, it should get partial list instead. The sending client could also set the level of information based on the number of files in the list (and possibly based on the configured upload speed too).