Thank for your post on our Community Forums @Pruacres!
I've been able to find this handy bit of information for you via this link
Talk Weekends: Zero-rated tariff applies to the first hour of direct-dialled local and national geographic voice calls only (numbers beginning 01, 02 and 03), Virgin Mobile numbers and 0870 numbers starting within the weekend (all day Saturday and Sunday) periods. Excludes indirect access, dial-up internet, 0845, other non-geographic numbers, 070 personal numbering, and 076 paging charge-bands. Re-dial before 60 minutes to avoid call charges. Calls over 60 minutes will be charged at standard rates, except for calls to mobiles which will be charged at 5p a minute. Charges apply outside of inclusive minutes. Fair usage policy applies. Inclusive 0870 numbers subject to limit of 1000 minutes or 150 calls per rolling 30 day period.
Standard rate phone calls are charged at 16p per minute