From Memory Alpha, the free Star Trek reference

WTRiker's wikipedia page

[edit] DYKBot quiz ranks

• 1-31-07 to 2-1-07: Cadet 4th class up to Cadet 2nd class
• 2-1-07 to 2-4-07: Cadet 1st Class to Lieutenant Junior Grade
• 2-4-07 to 2-6-07: Lieutenant
• 2-6-07 to present: Lieutenant Commander