Diddy Sentencing Set for October 3 in Federal Prostitution Conviction

Mark your calendars ... Sean "Diddy" Combs finally has a sentencing date for his prostitution conviction in his federal criminal trial.

Judge Arun Subramanian just officially set Diddy's sentencing for October 3 ... the same day he originally proposed last week, when Diddy was convicted on two charges of transporting male prostitutes for sex.

Diddy will remain in custody until his sentencing date ... and by that time, he will already have been locked up for over a year ... and his time served will go towards his sentence.

The music mogul faces a maximum sentence of 20 years -- a decade for each count -- but it's unlikely he gets sentenced to the max.

Diddy's defense and prosecutors are divided on sentencing guidelines ... Diddy's attorneys say sentencing guidelines start at 21 months, with prosecutors saying the sentencing guidelines start at 51 months.

Ultimately, it will be up to the judge.