How long will they hold my uni place?

I'm currently planning my options for this coming results day.

My firm choice is notorious for keeping students who've missed their offer waiting to see if they will still be given a place. I hold Edinburgh as my insurance. Ideally I would prefer to wait for my firm's response in the event that I miss my offer, but as they can take up to a week, I'm concerned Edinburgh might reallocate my place in the meanwhile, which could leave me without a uni place this cycle.

So my question is, how long will Edinburgh hold my place if I'm waiting for another response?

Thanks.