i20的program start date当天入境可以吗？

买不到再早的机票了，这种情况算不算晚于i20课程开始时间？需不需要提前联系学校

应该没什么影响，但保险起见可以给学校国际处发邮件让给签一封late arrival notice。我跟学校说明情况后学校给出的如下，希望有帮助

This letter will confirm that you, XXX, are granted permission to arrive no later than 23 August 2021, which is later than the Fall 2021 Semester reporting date of August 16, 2021, at XXX University. Please present this letter to the Immigration Officer or at the port of entry upon arrival to the United States.
Immigration Official: Please accept this document as official proof that XXX may arrive later than the Fall 2021 Semester reporting date of August 16, 2021. If you, a U.S. Consular Official or Immigration Inspector, have questions regarding this matter, please feel free to contact me. Thank you.

可以入境，也可以提前联系学校让他们知道你入境时间，如果海关问起，你就可以说学校知道且允许了的。（本科第一年有相似经历）