AWS SDK Error - Signature not yet current

I had the similar issue. I was running my CI server from an Ubuntu EC2 instance and that has the time out of sync. I synchronised the time with NTP suing

sudo ntpdate ntp.ubuntu.com

It started working fine.

I just encountered the same problem with a Django app deployed to AWS. The site error was really vague, but the error log that was emailed to me said, "JSONResponseError: JSONResponseError: 403 Forbidden{'message': 'Signature not yet current: 20150224T185106Z is still later than 20150224T185033Z (20150224T184533Z + 5 min.)'}" after a file path that pointed to Boto and Elastic Transcoder. Do the following on the server:

1. ntpq -p will tell you if you have ntp installed
2. If you don't have ntp, do sudo apt-get install ntp
3. sudo service ntp stop
4. sudo ntpdate -s us.pool.ntp.org will align your server's time with atomic clocks in the U.S. (this will need to be adjusted to your country)
5. sudo service ntp start

Good luck! You can read more here: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html#configure_ntp

If you are using windows, just set the current time and time zone automatically. It will resolve the issue.