Hey guys, please let me know if I got this right:

Pre 2005 - original dietz accepted

After 2005 - only modified dietz accepted

After 2010 - only geometrically chain linking is accepted (i.e. modifed dietz is not longer accepted)

Am I right? All this info is found on page 284 and 285 on volume 6.

What the book is not completely clear is if modified dietz is still accepted after 2010.

Modified Dietz does not require valuation of the composite / portfolio on the date of Large Cash Flows, just uses a weighting scheme .

Post 2010 , there is a requirement to value the portfolio on the date of all large cash flows . So the Time Weighted Rates of Return do not need to be calculated as an approximation

Geometric linking sub-period returns, say to arrive at quarterly return. You can consider a sub period as a monthly return for which you use modified dietz.

Recommendation is to evaluate portfolio at all external cashflows and if that happens dietz is no longer required.

You’re more or less correct, but I’d add that between 2005 and 2010 you can also use geometric chain-linking, but you can no longer use original Dietz.