If you have access to a fast Internet connection at all times, preferably one that you play a flat fee for, then you may not need to bother about when downloads start and end on the system.
If the connection is slow on the other hand, you may want to download files while the computer is idle to avoid that it impacts what you do on the system.
Another reason for this is if you have to pay for bandwidth but get unlimited access to it at certain times of the day.
Anyway, most users are probably making use of download managers to ensure that. There is the popular Internet Download Manager for example which can schedule downloads for you.
Download Plan is a new add-on for the Firefox web browser that provides a simpler solution. It allows you to set specific time intervals for downloads in the browser.
So, if you want downloads to only run at night, you can configure the extension to make that happen. It needs to be noted that you need to add downloads to Download Plan for that to happen. While that may turn some users away, it means that you can run downloads regularly as well at any time in the browser.
To add a download to the extension, simply right-click the download link and select the add to plan option from the context menu.
The second option that you have is to use Ctrl-Shift-V to paste a link from the Clipboard directly to the add-on's queue.
Each file you add this way is added to a queue which is automatically processed once the selected download period begins. It should be clear that Firefox needs to be open for that to happen. If it is not open, you can start it and downloads will be processed if the selected download period is active.
Download Plan accepts any link so that you can add html files, image links or any other type of content that can be downloaded to its queue.
As far as options are concerned, it is possible to change the download time interval (only one interval can be selected), and also the download directory and whether you want to be prompted whenever files get downloaded for the directory or not.
Download Plan is not the first download scheduler for Firefox. We have reviewed Download Scheduler back in 2013 for example which works in pretty much the same way as Download Plan.
With that said, if you want more control over when downloads start in Firefox and don't want to use a download manager to ensure that, then Download Plan or Scheduler may be right up your alley.