std.datetime TimeOfDay missing 'add' method?

[Ali Çehreli]

On 09/20/2012 09:02 AM, ixid wrote:
 > TimeOfDay's roll function refers to an add method

I see how "The difference between rolling and adding ..." implies that 
there is also an add() function just like there is a roll() function. In 
fact, adding is handled simply by operator overloading. You can add 
Duration objects:

   t += duration;
   auto newTime = t + duration;

Ali