Power Pivot :: Date Dimension - Create A List Of Months

I need to create a date dimension where the lowest level is month. I've seen examples which use the list function such as

Source = List.Dates(#date(2000, 1, 1), Duration.Days(DateTime.Date(DateTime.FixedLocalNow())-#date(2000,1,1)), #duration(1,0,0,0)),

The above increments by 1 day which is defined in the 1st argument of the #duration. My question is how can I dynamically change the value of this 1st argument such that its the number of days in the current month hence it will increment to only return the 1st date in the Month e.g

1/1/2000
1/2/2000
1/3/2000
etc..

I prefer to use an elegant approach if possible, the alternative would be return all dates, create a custom column from these dates which returns the month date - delete the dates column - get a distinct list of the month dates.