初步定在英文

I plan to go to Beijing on May 10th.I may set out several days later as there may be a shortage of train tickets during the Spring Festival holiday. 你要一定体现“初步”，就加个tentatively吧

The date is about 10th to 14th this month.

The date assigned varies from 10th to 14th this month.

时间初步定在这个月的下旬Preliminary scheduled in late this month.或者The time is initially scheduled in late this month.