If I understand your question correctly you are asking
How to factor the time it takes for test effort estimation is that correct? Below is how I define
Test Effort Estimation
The planning activity where you look at the entire
System Under Test and try to estimate the effort it is going to take to test the system. Effort obviously includes the time factor and should in some way try to answer
How long will the testing take?.
The important point I am willing to make here is that these are two different phases, ie Test Estimation and Test Execution and I do not see why you want to count both as testing time. It makes sense sometimes to look at the entire software life cycle of a feature to see how much effort all together went into that but then there are a lot more factors that will go into that ex test planning, effort estimation, reporting and analysis time etc.
I hope I answered what you were looking for, if not please let me know, and I would love to understand your question better.