这个直接引语怎么改成间接引语

Mum told me that Teachers~s day is on September 10th"
因为所说的事情是客观事实．．．．永远不能改变的．．．．所以后面的事态不能变

Mum told me that teachers' day would be (was) on september 10th.

Mum told me that teachers' day is on September 10th.