git reflog can show timestamps of when things happened with the --date flag
git reflog --date=iso
b3d1bab HEAD@{2019-03-20 16:09:19 -0400}: reset: moving to HEAD
b3d1bab HEAD@{2019-03-20 16:08:16 -0400}: reset: moving to HEAD
b3d1bab HEAD@{2019-03-20 16:08:04 -0400}: reset: moving to HEAD^