If the time you are interested in is not zero, you're allowed to cancel it and get the time from here.

如果你们关注的解不是零时刻,那么就可以忽略它,然后从这里解出时间

耶鲁公开课 - 基础物理课程节选

That's correct. So her answer was, if it was a full parabola, then we know it would've been at the ground before I set my clock to 0.

她说,如果运动轨迹为一条完整的抛物线,那么它在我们所设定的零时刻之前,就已经落地了

耶鲁公开课 - 基础物理课程节选

It knows that this particle happened to have a height of 15, at the time of 0, and a velocity of 10, and it is falling under gravity with an acceleration of -10.

这个质点恰好处在高度为15的地方,零时刻,初速为10,并在重力作用下以-10的加速度下坠

耶鲁公开课 - 基础物理课程节选