URGENT QUERY: H-1b and F1

[swasti]

I have a query Regarding H-1B

I am Master's student on F-1 visa.

So I got an offer from a company, with the joining date of 21 August 2017 and they are filing H-1B for me as well, but due to some circumstances I cannot finish off with my graduation before December, So now the company is deferring the start date till December,

So now my query is that if suppose my H-1B gets approved then:

When will my visa status change from F-1 status to H-1B?(is it after start date of joining or as soon as it gets approved)?
And If visa status gets changed in middle of the semester(like lets say October 2017), then will I be allowed to complete my Masters on H-1B visa?
And also I will be on H-1B visa and studying, not working till December. Is that even allowed?

I know these are so many questions but any input will be really helpful.

Thank you in advance

[raghvi]

I have a query Regarding H-1B

I am Master's student on F-1 visa.

So I got an offer from a company, with the joining date of 21 August 2017 and they are filing H-1B for me as well, but due to some circumstances I cannot finish off with my graduation before December, So now the company is deferring the start date till December,

So now my query is that if suppose my H-1B gets approved then:

When will my visa status change from F-1 status to H-1B?(is it after start date of joining or as soon as it gets approved)?
And If visa status gets changed in middle of the semester(like lets say October 2017), then will I be allowed to complete my Masters on H-1B visa?
And also I will be on H-1B visa and studying, not working till December. Is that even allowed?

I know these are so many questions but any input will be really helpful.

Thank you in advance

Is employer filing H1 as COS or as Consular process?

[swasti]

I think its Change of status. But I am not sure.