The phrase "time t" refers to a specific moment or point in time that is being referred to or studied. It allows us to talk about events or measurements at a particular instance instead of a general time period.
Sentences with «time t»
Then, the return period that I am interested would be for time t to (t +1 + one day). (money.stackexchange.com)
First time t - shirt buyer, first time commenter... So excited for you & your family's journey to your little one. (theletteredcottage.net)
In other words, security C did not exist in the portfolio from time t to t +1. (money.stackexchange.com)