generate_series(date '2001-01-05', date '2020-12-31', interval '2 weeks') will return every payday from jan 5 2001 to the end of 2020 (assuming the 5th was payday, change the start to jan 12 if that was instead).
pgsql-general by date:
Соглашаюсь с условиями обработки персональных данных