PTCL has introduced a new tariff reduction plan from October 1st, 2008. It will be applicable on Sundays only. The call charges for local, NWD & mobile calls will be as follows:
Local Calls: Rs. 1 for 3 mins. (On Net including Vfone)
NWD Calls: Rs. 1 for 1 min. (On Net including Vfone)
Mobile Calls: Rs. 1.25 for 1 min.
This tariff reduction will be applicable on all PSTN subscribers. However, Sunday Half Rates will not affect Pakistan Plus subscribers for NWD calls as their NWD minutes are already free till 2500 minutes but they will be able to make local calls and mobile calls on half rate. International calls will be charged as per regular/current tariffs.
Half Rate Sundays is primarily a promotion, it will stay in effect till further notification for termination.
Source & for more info: