Mossimo Giannulli was set to be released from home confinement April 17, which is a Saturday, but it's common policy to grant release on the last preceding weekday if their freedom date falls on a weekend.

So, according to the Federal Bureau of Prisons, Lori's hubby was eligible to get off home confinement Friday, April 16 ... which is what just happened.

As we reported ... Mossimo was originally supposed to be locked up behind bars until the 17th, but got sprung a couple weeks early to serve out the remainder of his sentence at home.

Of course, he tried to get a much earlier release in January over COVID-19 concerns, but the judge shot him down, claiming his worries weren't enough to justify it.

This happened about a month after Lori got released -- just after Christmas -- after serving nearly 2 months for her role in the notorious college admissions scandal.

As you'll recall ... Lori pled guilty last May to 1 count of conspiracy to commit wire and mail fraud. She and Mossimo were accused of paying $500k in bribes to get their daughters into USC and faking a photo that made it look like the girls were college-caliber rowers.