| Clue | Source | Date |
|---|---|---|
| Happening either 2 or 8 times every 28 days (8) | The Guardian Quick | 16 Jan 2025 |
| Every 14 days | Eugene Sheffer | 30 May 2024 |
| Once a fortnight (8) | ||
| Every 14 days | The Times Concise | 20 Aug 2023 |
| 26 times a year | The Guardian Quick | 10 Mar 2023 |
| Shop ineffectively as stated every fortnight | ||
| Happening every 14 days | Family Time | 02 Feb 2020 |
| 100 times a year, roughly | The Washington Post | 27 Apr 2019 |
| 100 times a year, roughly | LA Times Daily | 27 Apr 2019 |
| 100 times a year, roughly | ||
| How some are paid |