"Issued certificate not yet valid." with wget?

I am getting the following error when using wget to fetch a file:

  Issued certificate not yet valid.
To connect to www.atlassian.com insecurely, use ‘--no-check-certificate’.

Testing with openssl returns a similar message:

Verify return code: 9 (certificate is not yet valid)

Solution 1:

Your system clock is likely set in the past.

Solution 2:

When checking the ssl certificate 'notBefore' date with openssl it was valid... It turns out my calling machine's system time was way in the past.