Altrincham supporters are being encouraged to wear red or white clothing and bring balloons and flags to the game to create a special atmosphere.
Gary Warrington, the supporter behind the idea said, "This is our cup final. I urge anyone who has supported Altrincham in the past to show their support again.
"The club deserves to be rewarded for all the hard work they have done by getting support from the people of Altrincham.
"So if you have nothing to do between 3 and 5pm get down to Moss Lane. Or even if you have plans, cancel them and come along to support the team.
"If Tamworth can get more than 2,000 people down to their last home game then so can we.
"Let's create a carnival atmosphere to give the lads a real lift as they run out onto the pitch."