11:04 AM PT -- TMZ has obtained Billy Ray Cyrus' docs -- and he lists their date of separation as May 22, 2024. In terms of why he filed for divorce, BRC is citing irreconcilable differences ... as well as "inappropriate marital conduct."

Billy is also asking the court to grant him an outright annulment, claiming the marriage was obtained by fraud. It also looks like Billy gave Firerose a deadline of May 24 to get the hell out of the house ... while also initially putting up $500/night over a period of ten days for temporary housing.

After that ... the docs say Billy will pay Firerose $5,000/month for her to obtain suitable housing in Tennessee for a period of 90 days, or until the divorce is finalized -- whichever occurs first. He's gotta pay her the $5k on the first of each month.

The ink is barely dry on Billy Ray Cyrus' marriage to singer Firerose -- and he's already pulling the plug ... TMZ has learned.

Billy Ray filed to divorce his latest bride last month -- this less than a year after they got hitched. The divorce case notes there are no minor children between them ... and it looks like Billy submitted his paperwork in late May, without anyone noticing.

With only 7 months under their belt as a married couple, Billy Ray and Firerose did not have any children while together ... so no child support agreements to hammer out here.

The divorce marks the end of Billy Ray's third marriage ... he was married to Cindy Smith from 1986 until 1991 when they divorced. His second wife is Tish Cyrus, they were husband and wife for 3 decades and had three kids together -- including Miley, Braison and Noah, --until Tish filed for divorce in April 2022.

Billy Ray and Firerose got engaged in August '22, having met back in the day on the set of "Hannah Montana." They also released music together in '21, and in October '23 they got hitched. Firerose posted wedding pics of their nuptials this past April, and a loving caption.

She wrote, "6 months ago I married this man. 🤍 Life isn’t always easy… but it sure helps when your husband’s also your best friend. Thank you Lord!" Firerose has been posting Billy on her timeline like nothing is amiss ... her latest IG upload talks about her sobriety journey.

As for Billy ... he hasn't been posting Firerose very much at all lately -- instead, he's plugging new music, while reminiscing on the old days ... including a shout-out to his daughter, Miley.

What's interesting is that before late April ... Billy was posting Firerose a ton, his whole feed was littered with pics of the two of them. Now though ... she's noticeably absent on his IG.

Even more telling ... the fact Billy Ray no longer follows Firerose, and vice versa.

It'll be interesting to see how the split affects Billy's relationship with Miley, Tish and Noah ... remember, there's been some drama there of late.

As for Tish, she wasted little time moving on too ... she's now married to Dominic Purcell and they seem to be going strong despite allegations of a love triangle with Noah.

Just another day in the Cyrus circus ... talk about a whirlwind!

We've reached out to Billy's camp, so far no word back.