The match will be played at Bangor University Stadium (14:30 GMT).
The other semi-final sees Caernarfon Town of the Cymru Alliance play Welsh Premier outfit Bala Town at The Corbett Sports Stadium in Rhyl (17:15 GMT).
TNS - champions for the past three years - are the only team left in the tournament who have won it before.

The Tigers, who have not won a major trophy since 1986, finished fifth in Super League last year.
"We want to be competing in finals and we've shown that we can do that," Powell told BBC Radio Leeds.
"I think we're capable of winning something. I'm pretty confident that we have got what we need and we have to believe that we can win something."
He added: "We'd like to think that we will be there or thereabouts. All my communications to the players have been that it is time to take the next step. We'll find out in a month or so if we are going to do that.
"I think you see pretty quickly what you have got in your ranks and we have got good depth, balance and we can play a bit. Whether we can defend tough enough to be able to win something is what we'll find out."
Powell took over the Tigers in May 2013 after the departure of Ian Millward.
The team are preparing to go on a pre-season camp in Lanzarote and Powell is hopeful the change of scenery will be beneficial for the players.
"The start of the season does give you tough conditions and soft pitches so you need to train in that to get you ready but it'll be great to get a different environment," he added.
"It's not something we've done in my time here and hopefully it can give us that extra push to help us crack that top four."
Holders The New Saints (TNS) will have to travel to Bangor for their Welsh Cup semi-final against Gap Connah's Quay on 1 April.
[NEXT_CONCEPT]
Castleford Tigers coach Daryl Powell believes he has the squad in place to compete for silverware this season.