LITTLE KNOWN FACTS ABOUT PNL.

$ In the "operate situation" you liquidate the portfolio at $t_1$ realising its PnL (let me simplify the notation a little)$begingroup$ I estimate daily pnl on a CDS place utilizing the spread improve periods the CS01. Even so I want to estimate the PnL for a longer trade that has long gone from the 5Y CDS into a 4Y with related coupon payments. Le