Duration.total

long total(string units)() if (units ==  "weeks" ||
            units ==  "days" ||
            units ==  "hours" ||
            units ==  "minutes" ||
            units ==  "seconds" ||
            units ==  "msecs" ||
            units ==  "usecs" ||
            units ==  "hnsecs" ||
            units ==  "nsecs")

@property const nothrow @nogc

Returns the total number of the given units in this Duration. So, unlike split, it does not strip out the larger units.