angular date formats
'short': equivalent to 'M/d/yy, h:mm a' (6/15/15, 9:03 AM).
'medium': equivalent to 'MMM d, y, h:mm:ss a' (Jun 15, 2015, 9:03:01 AM).
'long': equivalent to 'MMMM d, y, h:mm:ss a z' (June 15, 2015 at 9:03:01 AM GMT+1).
'full': equivalent to 'EEEE, MMMM d, y, h:mm:ss a zzzz' (Monday, June 15, 2015 at 9:03:01 AM GMT+01:00).
'shortDate': equivalent to 'M/d/yy' (6/15/15).
'mediumDate': equivalent to 'MMM d, y' (Jun 15, 2015).
'longDate': equivalent to 'MMMM d, y' (June 15, 2015).
'fullDate': equivalent to 'EEEE, MMMM d, y' (Monday, June 15, 2015).
'shortTime': equivalent to 'h:mm a' (9:03 AM).
'mediumTime': equivalent to 'h:mm:ss a' (9:03:01 AM).
'longTime': equivalent to 'h:mm:ss a z' (9:03:01 AM GMT+1).
'fullTime': equivalent to 'h:mm:ss a zzzz' (9:03:01 AM GMT+01:00).