List should show timestamp for recent files instead of current year

[rsichnyi]

No description provided.

[pohmelie]

First of all, when I implement list, I read, that there is no standard for list format. So there is nothing good and nothing bad with this pull. So, it will be accepted, since human readability. 👌

• What is the reason to change datetime.datetime.fromtimestamp to time.time?
• Why half of year branching?
• More obvious way to find delta is timedelta.days, I think.

[rsichnyi]

it's a copy-paste from asyncssh (https://github.com/ronf/asyncssh/blob/master/asyncssh/sftp.py#L3372), i didn't bother to improve the code - it's simple enough

regarding 6 month it's how nx ls -l works, see http://git.savannah.gnu.org/cgit/coreutils.git/tree/src/ls.c#n4015