Diamond was also sentenced to 15 months' probation and was ordered to report to jail on Sunday.
Last month, a jury convicted Diamond on two misdemeanor counts of disorderly conduct and carrying a concealed weapon. He told the jury at the time that he drew a knife in the bar in order to scare another group of patrons who were antagonizing him and his girlfriend.
Diamond was found not guilty of a more serious felony charge of recklessly endangering public safety. His girlfriend, Amanda Schutz, was convicted of disorderly conduct and fined $500.
Judge Paul Malloy said he handed down the sentence "to send a message to the community that we're just not going to live like this," according to the AP. Diamond had no comment.