Currently I am living in a part of rural Virginia, where the only option for internet is ViaSat internet satellite. The service has its ups and downs, but the worst part are the data caps, and they are cell phone low. In fact the highest plan I can buy is 25GB of data transfer and that is about $140 per month.
One thing that I really miss is the ability to have my Dropbox synced at all times. The data transfers can be high if I am putting videos and photos into my Dropbox. Dropbox’s application currently allows you to throttle the bandwidth, but it’s either on or off…
ViaSat does offer something nice… every morning from Midnight to 5AM they shut off the meters allowing unlimited usage. I decided to leverage this and make Dropbox sync only during this free window.
Doing this on a MAC boils down to just two things.
1. Create applications to launch and stop dropbox.
2. Schedule a daily task to START Dropbox.app at 12AM and to STOP Dropbox.app at 5AM.
Create applications to launch and stop dropbox
On the Mac there is an awesome program called Automator that lets mere mortals create easy programs that can do various things. I highly recommend looking into this capability. It is really handy. For this problem, we will use automator to both Launch and kill the dropbox app at the times we want.

1.3. Select “Application” to create a new application. (This first one will be setup to open the dropbox app)

1.4. Select Utilities on the left.
1.5. Drag the “Start Launch Application” task into the workflow pane on the right so it looks like this.

1.7. Perform a similar process to create another Automator app to “Quit Application.” Make sure to assign the dropbox.app in the dropdown box, and also uncheck the “ask to save changes” confirmation.
Next we will schedule these applications (a.k.a. workflows, scripts, etc.) to run automatically in iCal

2.1 Create a new Event in iCal on the first day you want this application to run.
2.2 Setup to start at 00:00 i.e. midnight.
2.3 Under alerts, setup a custom alert to open a file. Choose the Start dropbox app we made.
2.4 Alert timing should be “At time of event” to make sure this fires off at the time we want.