Ok KoolReport Gurus, I am creating a payroll report and need to add up the total time worked per employee. Data is in MSSQL time format. I know in MSSQL I can do something like this:

select cast(dateadd(millisecond,sum(datediff(millisecond,0,cast(<time column> as datetime))),0) as time) FROM table>

but how to do it in a KoolReport function? So in the user group I already have some other aggregate functions such as:

"{countAvailable}"=>function($store){
                    return $store->filter("<column to count>",">",0)->count();
                }

But times have got me stumped.