First of all this is not a duplicate of this question
I am not asking about permanent removal of the sacred thread, but in what daily activities is this to be removed ? Is it to be removed prior to ablutions, bathing, sleeping, procreation etc ?
Also from the accepted answer in the aforementioned linked question
He should, daily, study the Vedas and put on his sacred thread. He should speak the truth and control his passion. [Such conduct] leads to the attainment of emancipation.
So I assume the sacred thread is not worn all times.