Duration.TotalMinutes Function of Power Query
The Duration.TotalMinutes function in Power Query, returns the total number of minutes in a Duration value.
Syntax
 Duration.TotalMinutes(duration as nullable duration) as nullable number 
• duration: A duration type input (e.g., from #duration(days, hours, minutes, seconds)). 
 Returns: It specifies the total minutes as a decimal. 
Example: Find the total minutes spanned by a duration value.
Power Query M
let
    source = Duration.TotalMinutes(#duration(1, 2, 30, 0))
in
    source  The output of the above code is 1590.
 Calculation Converts the entire duration into minutes: 
 • 1 day = 1×24×60=1440 minutes 
 • 2 hours = 2×60=120 minutes 
 • 30 minutes = 30 minutes 
 • 0 seconds = 0÷60 = 0 minutes 
 Total = 1440+120+30+0=1590 minutes