Can I get an extension on the deadline to the end of the week?

on为错误，应改为of:

Can I get an extension of the deadline to the end of the week?

Can you extend the deadline to the end of the week?

动词extend改为同源名词extension，原来但宾语由介词of 引出，原状语不变。不过，现在of 和 to二个介词短语都是名词extension的定语了。