While his players are taking on one half of the Old Firm, the 30-year-old will be tying the knot with fiancee Jennifer.
The manager initially thought he would only miss a home tie with Stranraer when the couple were planning their big day.
However after Rangers were placed in Scotland's bottom tier this summer, a quick check of the fixture list confirmed his worst fears.
Greig said: "I got engaged in December before I got the Stirling job and everything was all booked.
"When the fixture list came out we were meant to be playing Stranraer at home and now it has ended up being Rangers.
"I asked Jen to put the wedding back but she was having none of it.
"Some things are more important than football, though."
The fixture is one of a few Gers away games that has not been moved for live television coverage.
Greig said: "The wedding starts about two so I will be getting pictures taken and trying to get on my phone to check the score I think."
Greig became the youngest manager in British football when he took over the top job in January.
The then 29-year-old was appointed caretaker boss after the departure of Jocky Scott but convinced the executive board he had what it takes by leading the side to two successive wins.