The Rail, Maritime and Transport Union has confirmed guards and drivers will walk out for 24 hours between 00.01am and 23.59pm on Tuesday April 4.
The union have been embroiled in a dispute with Southern Rail owners Govia Thameslink for months over the safety impact of driver-only trains and the removal of guards from services.
But the union has said it will reconsider the strike date if the company gives them a date for talks to take place.
RMT general secretary Mick Cash said: ‘RMT members on Southern Rail have been fighting for safety and access for nearly a year now and it is disgraceful that we have continued to be carved out of the talks process.
‘That is a kick in the teeth for our members.
‘This dispute needs to be pushed forwards and RMT would be prepared to reconsider our action if we get a commitment to a firm date for genuine and meaningful talks.’
Responding to the new strike date, a Southern spokesperson said: ‘We’ve not received any correspondence from the RMT on this matter. When we do we’ll review it and respond.
‘In the meantime, they have announced a new strike date and we’ll plan accordingly if it goes ahead.
‘We’ve been able to run over 90% of our trains for our passengers on recent RMT strike days and we will plan to run a comprehensive service again.’