- the "exact method," whereby we revalue the portfolio for any cash flow
- the "linked IRR," where we geometrically link subperiod (e.g., monthly) returns which were derived using the internal rate of return (IRR); this is similar to the Modified Dietz formula
- the time-weighted method, where instead of geometrically linking, we link returns based on the length of time between flows.
In no way do we weight time in time-weighting. Granted, we weight cash flows based on their time in the Modified Dietz and Linked IRR, but this wasn't the source of the expression. Time-weighting simply means that we are eliminating or reducing the impact of cash flows. That's it! No time weighting.