South Korea has proposed that the two rival Koreas begin arranging reunions next month for families separated by the 1950-53 Korean War.
Seoul came up with the dates on Monday after the North unexpectedly announced on Friday it was willing to hold the event, three years after the latest reunions were held.
Pyongyang had called on South Korea to choose the dates, marking the latest in a series of conciliatory gestures.
Seoul's Unification Ministry said it sent a message proposing the reunions take place from February 17-22 at a North Korean mountain resort.
"We hope that the North will show positive reactions to our proposal and that the family reunions will be held smoothly to open new opportunities in inter-Korea ties," the ministry said.
North Korea's situation is always changing.
Millions of Koreans have been separated since the Korean War ended with an armistice, not a peace treaty.
The two Koreas share one of the world's most heavily fortified borders and bar ordinary citizens from exchanging letters, phone calls and emails.
About 22,000 North and South Koreans have had a chance to briefly meet with their long-lost relatives during a period of detente but family reunions have not been held since October 2010.
A month after that reunion, North Korea launched artillery at a South Korean front-line island, killing two civilians and two marines.
The Koreas had agreed to resume the humanitarian programme last September but North Korea abruptly cancelled the plan.
The South Korean Defence Ministry has expressed concern over the sincerity of North Korea's recent gestures to improve the South-North relationship.
Seoul has so far rejected the North's overall offer to take a series of steps to ease tensions, saying Pyongyang must take nuclear disarmament steps first.
"North Korea's situation is always changing," said South Korean Defence Ministry spokesman Kim Min-seok.
"North Korea is currently putting forward a peace offensive, but we will have to wait and see what their direction will be, how sincere they are, and how much effort they are putting towards peace on the Korean peninsula," he added.