Answers:
This is done at the server where on earth the lease is issued. If that's your broadband router, near is mostly a setting for the number of hours (or days?!) previously a lease expires. (Check out my screenshot below to see one example).
The time can be in step to suit your requests.
But it's other done at the server or appliance from where on earth the address is issued.
You don't set it, the DHCP server lease for 24 hours.
If you're discussion around a home network setup, afterwards it'll be contained by the router config page. On my router, I don't reflect it works properly anyway. I'd use static IPs for a home make friends.
On the DHCP server. If this is on a home meet people, this is usually your ASDL router. If you'retalking just about your internet IP address, afterwards you will enjoy no control over this as itt's set by your ISP.. Ask them just about getting a "Fixed IP" if you want to save your IP address constant for any length of time.