自始至终

from start to finish

不自今日始。

It doesn't start today.

不知始于何时

it's not known when it started

游行至下午５时始毕。

The parade won't finish until 5 o'clock in the evening.

那时我始知来之非易。

At that moment I realized it hadn't come easily.

不断学习，始能进步。

Progress can only be made through constant study.