Friends say the '3' singer is so strictly guarded by dad Jamie Spears she has lost track of the time and days of the week.

A source told FoxNews: "She is so out of it she just doesn't care anymore. She just does what she's told and is totally in her world.

"She'll even call people at all hours of night for a general conversation and acts like it's the middle of the day or something."

Jamie – who took charge of Britney's personal and financial affairs after her emotional breakdown in January 2008 – is so determined to keep his daughter under control he is reportedly systematically firing her staff so she doesn't have the chance to get close to anyone.

The source revealed: "He's really trying to clean up her image. He's making a lot of changes to the people around her. Everyone is a bit on edge they could be the next one to be replaced.

"Britney's family has seen what happens when she gets too close to outsiders and they lose control, they don't want it happening again."

Jamie blames Britney's relationship with former manager Sam Lutfi and paparazzo Adnan Ghalib for his daughter's breakdown.

He has taken out restraining orders against both men.