When did you post on Face book?
The post on December 11, 2016 discussed how to download data for an individual user's posts to Facebook. Don't miss that the downloaded data will include an html file named 'Security' which will have information for each individual login showing the precise time and the device used to access Facebook. See this excerpt:
Friday, November 7, 2017 at 10:04pm EST IP Address: 244.213.87.52 Browser: Mozilla/5.0 (iPhone; CPU iPhone OS 7_1 like Mac OS X) AppleWebKit/601.1.4 (KHTML, like Gecko) Mobile/12B411 [FBAN/FBIOS;FBAV/22.214.171.124.11;FBBV/4950413;FBDV/iPhone4,1;FBMD/iPhone;FBSN/iPhone OS;FBSV/5.1;FBSS/2; FBCR/AT&T;FBID/phone;FBLC/en_US;FBOP/3] Cookie: ...-