The quadrangular international tournament will see double-header internationals played on three successive weekends in Durban, Nelspruit and Pretoria for the first time and will also involve the hosts, plus Italy and Samoa.
The London-born lock qualifies for Scotland through his late grandmother from Partick in Glasgow.
Tim told the Evening Times: "I thought the whole international thing was going to be a dream I would never realise.
"But when I played for Scotland 'A' against the English Saxons it did give me belief I could still make it into the full Scotland set-up.
"My late grandmother stayed in Partick. It's funny because although I never visited her there as a kid, I now stay only a few streets away from where she lived in Hayburn Street.
"I know she would have been very proud, so I hope she is looking down with a smile.
"With 14 Glasgow players in the squad, I will certainly not be homesick – I think to have so many Warriors in there is a huge complement to how our season has gone."
The ground-breaking matches take on added significance as both South Africa and Samoa are in Scotland's pool at the 2015 Rugby World Cup in England.
Looking ahead to Saturday night's Pro12 play-off semi-final with Leinster, Tim says physicality will be the key to Glasgow hopes.
He said: "We have to play on the front foot and the only way we will do that is if we produce a performance of the utmost physicality.
"Leinster are so good at the breakdown but we are going to have to go there and take that dominance away from them."