6:41 PM PT -- The Sitch responded to his sentencing on social media, saying ... "We are very happy to put this behind us. Thank you So much for all the Love & Support."

10:43 AM PT -- Situation was sentenced to 8 months behind bars and two years of supervised release. His attorney, Henry Klingeman, tells TMZ, "Mike accepts the Court's judgment. He is looking forward to marrying his college sweetheart, Lauren Pesce, next month and moving forward together after he serves his sentence."

Mike looked relaxed on his way out of court, holding Lauren's hand and flashing a peace sign to the group gathered outside.

9:45 AM PT -- Situation's brother, Marc -- who was also indicted at the same time on tax fraud charges -- has just been sentenced to 2 years and a $75k fine.

It's D-Day for Mike "The Situation" Sorrentino -- who just arrived at federal court in Newark, NJ to find out if he's going to prison for evading his taxes -- and he's got the whole 'Jersey Shore' crew with him.

The 'Jersey Shore' star is set to be sentenced Friday for tax evasion. As we reported, Sitch pled guilty way back in January. He could be looking at a max of 5 years in prison, but even prosecutors have been pushing for the judge to go easy on him.

Pauly D, Ronnie, JWoww, Vinnie, Snooki and Deena were all at the courthouse bright and early to show some love to their friend.

Since entering his plea, Mike got the court's approval to travel to Florida and Nevada to shoot the 'Jersey Shore' reunion.

Mike's sentencing was originally scheduled for April 25, but his lawyer was able to buy him more time while resubmitting docs as part of his plea deal.

His sentence should be handed down shortly. Stay tuned ...