Schedule commands in LFTP using "at"

You can schedule downloads and uploads in LFTP in a simple manner by using the `at` command. Anything following the syntax described in this image below should work.

Mirror/download a remote folder two hours from the current time, using 10 connections + segmentation:

at now + 2 hours -- queue mirror --use-pget-n=10 yourdirectory/

Mirror/download a remote folder at 1AM tomorrow, using 10 connections + segmentation:

at 1:00 tomorrow -- queue mirror --use-pget-n=10 yourdirectory/