title: How to set epoch for std::chrono::steady_clock in C++?
body: <p>I would like to get current time in milliseconds since a specific epoch e.g. Jan 1, 2016.  </p>
  
  <p>The reason to do this is to avoid using 8 bytes for std::chrono::milliseconds.<br>
  I would like to store the result in a 4byte data type instead.  </p>
  
  <p>std::chrono::steady_clock() uses default epoch which is unspecified.  </p>