Janowitz was formerly part of the German Empire. In the German Empire, the place was called Jannowitz (Wartheland).
The place is now called Janowiec Wielkopolski and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Janowitz (Bz. Bromberg) | German Empire | Znin | before the Versailles Treaty |
| Janowiec | Poland | Żnin | after the Versailles Treaty |
| Janowitz | German Empire | Dietfurt (Wartheland) | 1939 |
| Jannowitz (Wartheland) | German Empire | Dietfurt (Wartheland) | 1939 |
| Janowiec Wielkopolski | Poland | Żnin | 1945 |
| Janowiec Wielkopolski | Poland | Bydgoszcz | 1992 |