| Kostroma Wieselburg | Central European Time | 01:00 |
| Kostroma Palmyra | Eastern Time | 07:00 |
| Kostroma Zikhron Ya'akov | Israel Time | 00:00 |
| Kostroma Cidade Ocidental | Brasilia Time | 06:00 |
| Kostroma Zillah | Pacific Time | 10:00 |
| Kostroma Palmhurst | Central Time | 08:00 |
| Kostroma Zirakpur | India Standard Time | -02:30 |
| Kostroma Pampatar | Venezuela Time | 07:00 |
| Kostroma Zofingen | Central European Time | 01:00 |
| Kostroma Panama City Beach | Central Time | 08:00 |
| Kostroma Zollikerberg | Central European Time | 01:00 |
| Kostroma Pamukkale | Turkey Time | 00:00 |
| Kostroma Panchwad | India Standard Time | -02:30 |
| Kostroma Panchkula | India Standard Time | -02:30 |
| Kostroma Panania | Eastern Australia Time | -07:00 |
| Kostroma Wyomissing | Eastern Time | 07:00 |
| Kostroma Wyong | Eastern Australia Time | -07:00 |
| Kostroma Wynn Vale | Central Australia Time | -06:30 |
| Kostroma Wynnewood | Eastern Time | 07:00 |
| Kostroma Wynyard | Eastern Australia Time | -07:00 |
| Kostroma Wythall | United Kingdom Time | 02:00 |
| Kostroma Wytheville | Eastern Time | 07:00 |
| Kostroma Xaafuun | East Africa Time | 00:00 |
| Kostroma Xàbia | Central European Time | 01:00 |
| Kostroma Xalapa | Central Time | 08:00 |
| Kostroma Xalapa Enríquez | Central Time | 08:00 |
| Kostroma Xalisco | Mexican Pacific Time | 09:00 |
| Kostroma Woy Woy | Eastern Australia Time | -07:00 |
| Kostroma Wrightsville | Eastern Time | 07:00 |
| Kostroma Wrightsville Beach | Eastern Time | 07:00 |
| Kostroma Woods Cross | Mountain Time | 09:00 |
| Kostroma Worb | Central European Time | 01:00 |
| Kostroma Woody Point | Eastern Australia Time | -07:00 |
| Kostroma Woolloongabba | Eastern Australia Time | -07:00 |
| Kostroma Workum | Central European Time | 01:00 |
| Kostroma Worrigee | Eastern Australia Time | -07:00 |
| Kostroma Wörrstadt | Central European Time | 01:00 |
| Kostroma Xaxim | Brasilia Time | 06:00 |