Something with the Telephone (1979)

Based on the fantastic story by Kir Bulychyov "Can You Ask for Nina?".
Guests gathered in Vadim Nikolayevich’s apartment to celebrate the 1979's New Year with a cheerful company. The landlord unsuccessfully tries to reach his friend Nina. He, dialing a number, gets to a girl who is also called Nina. Her answers seem strange to Vadim Nikolayevich until he realizes that he is in some unusual way talking with a child from Moscow in 1942.