Duration
Returns a string representing the specified duration in the specified format.
Arguments
This function has the following arguments:
 Duration
Duration: Numeric value specifying the duration, in milliseconds, to be formatted.
 Duration Format
Duration Format: Text string specifying the format of the function result. This string may contain 0 or more of the characters 
d, 
s, and 
. (for example 
ds) indicating that days, seconds, or milliseconds are to be included, in addition to hours and minutes, in the returned string. If no 
Duration Format is specified, the string is returned in the form exemplified by 
15:32 (hours:minutes).
The function returns a text string.