Schedule Automatic Downloads in Firefox : Download Scheduler
This is a very simple extension for Firefox to allow you to schedule downloads to start at a later time. The usual use-case is for people who have a plan with their internet service provider for a limited amount of monthly usage but with the exception of an off-peak time.
Firefox Addon : Download Scheduler (Install)
This extension can allow you to setup those files for the off peak time and enjoy some good sleep without worrying about exceeding your monthly usage.
It has now been updated to work with Firefox 3.6. It is very simple to use once installed:
1) Configure the time under the Tools -> Addons -> Download Scheduler -> Options
2) Right click a link a choose ‘Schedule Link As…’ rather than ‘Save Link As…’
3) Leave Firefox running until that time.
Any downloads that don’t finish during the set period will automatically enter pause mode when time is up. You can also view/cancel any waiting scheduled links by going to Tools -> Download Scheduler.
Also Read : Best Tips to Make Firefox 3+ Faster