[Bug-wget] Timestamping vs incomplete downloads

[Dave Warren]

Currently when a download with timestamping enabled gets interrupted, 
the timestamp of the resulting file ends up being the current time and 
when wget is re-executed after connectivity is restored the local file 
is then seen as newer and skipped.

robocopy handles this a little differently, by setting a date far in the 
past as a way of ensuring that on a subsequent execution the transfer 
can be resumed.

Is there a better way to handle this situation in wget? A way to force 
an old date on the file? I'd be happy with a fixed "in the past" date, 
the service supplied date minus a second, etc. Or some way to detect 
that the file is incomplete (too small) on a subsequent run?