Bash shell scripts can be used to do a variety of things. It is very easy to schedule the script to run under crontab. It would be helpful if we log the steps with date time and a message. It can be done as follows.

echo '['`date +%F\ %T`'] Downloading file abc'
[2012-09-06 23:20:16] Downloading file abc

NB: The date command is enclosed in back tick, not single quote.