RSS Feed Refresh: Every Day

Quick question – if I set my RSS feed refresh to ‘Every day’ instead of ‘Every 15 minutes’ – what time will it refresh, and how will I know if my feeds are up to date?

Also, what if my computer is closed at night? Will it skip the daily refresh due to the computer being turned off, or will it refresh when I open my computer and connect to the Internet again?

Thanks.