Fortnightly / Twice monthly
Different meaningsFortnightly means every two weeks; twice monthly means twice in each calendar month. They are not interchangeable.
Fortnightly
Use when
Something happens once every two weeks.
Example
“The fortnightly payroll is processed every other Friday.”
Twice monthly
Use when
Something happens twice in each calendar month, usually on stated dates.
Example
“Claims are paid twice monthly, on the 15th and final working day.”
Quick check
fortnightly treated as twice monthly, two pay dates every month described as fortnightly, schedule without actual dates
Usage note
A fortnightly schedule normally produces 26 occurrences a year, while a twice-monthly schedule produces 24. State the dates when timing affects pay, deadlines or attendance.