How long does it take for Open Work Permit (Spouse)?

[sabrina006]

Hi,

My husband has got student visa (MSc). His semester is going to start in September 2018.
Now, I would like to apply for OWP.
My queries are -

1. When can I apply for OWP?
2. Do I need any invitation letter from my husband's university?
3. How long does it take to get the OWP?
4. Which one is faster - TRV or OWP?
5. Can I go with my husband (he is planning to move in mid August)?

Thank you.