CoS expiry days calculations

[Irfanlibra2017]

Hi.

Hope you folks are good. I have a question regarding cos expiry. If my company had an open defined cos from home office since last two months and now they have shortlisted me after the interview process. They have put my details in the dcos to generate my cos letter. How does the cos expiry works, does it starts from the day cos letter is generated with my name or the day when home office issued dcos.

Thanks

[CR001]

Starts from date it is assigned to you.