"And much of his repertoire,pieces like, oh,Syncopated Clock and Sleigh Ride and things like that we play to this day."

VOA: standard.2010.07.28

First of all, negative time should not bother anybody; t=0 is when I set the clock, I measured time forward, but yesterday would be t = -1 day, right?

首先,负的时间对我们不存在任何干扰,t=0使我们设定的初始时间,我是用顺序计时,所以昨天就可以记为-1天,对吗

耶鲁公开课 - 基础物理课程节选