title: Moment.js - Can't calculate .diff between dates properly if they are in different days
body: <p>Can someone explain me why this isn't working properly. Below is a code that is using moment.js to calculate differance between CURRENT time and my variable times.</p>
  
  <pre><code>           //breakfast
             var breakfasttimeleft = moment(person.breakfast, 'HH:mm');
             console.log("Person breakfast is at:  " + person.breakfast + " -- Current time is at: " + currenttime);
             console.log(breakfasttimeleft.diff(now, 'minutes'));
  
             //lunch
             var lunchtimeleft = moment(person.lunch, 'HH:mm');
             console.log("Person lunch is at:  " + person.lunch + " -- Current time is at: " + currenttime);
             console.log(lunchtimeleft.diff(now, 'minutes'));
  
             //dinner
             var dinnertimeleft = moment(person.dinner, 'HH:mm');
             console.log("Person dinner is at:  " + person.dinner + " -- Current time is at: " +  currenttime);
             console.log(dinnertimeleft.diff(now, "minutes"));
          })
  </code></pre>
  
  <p>HERE IS THE OUTPUT:</p>
  
  <pre><code>CONSOLE LOG
  Person breakfast is at:  18:35 -- Current time is at: 18:35
  0
  Person lunch is at:  23:35 -- Current time is at: 18:35
  300
  Person dinner is at:  04:35 -- Current time is at: 18:35
  -840
  </code></pre>
  
  <p>Dinner is totally messed up on some places, like on above and on others it works perfectly fine.
  Basically.. it doesn't know how to look up hours if the other date is in another day, so instead it will look up differance between these 2 hours in current day.</p>
  
  <p>18:35 to 04:35. It is suppose to be from 18:35 to 04:35 in the morning, which is around 10 hours. Instead what it does is calculates time from 04:35 in the morning to 18:35 later that day.
  How can i fix this to work properly?</p>
  
  <p>It appears I have to state a day aswell.. how can i format it so it is Day + Hours + Minutes</p>